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SGKent 
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Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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 Posted: Mon Mar 20, 2023 5:13 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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Ray I agree with you in that accessories can add up. I ran a nice stereo in a 1971 bus with an amp, along with halogens and fogs - and never once over loaded the 38 amp generator in the bus. It might flare a little below 900 RPM. I can see where going to a 70 - 75 amp would be beneficial in cold weather when an aux heater is used. But, my brother Rick had type 3 that when I was done rebuilding the engine, putting new rubber ducts and boots in, you could cook someone out of that car in cold weather. Buses are larger and lots of uninsulated glass. Takes a lot of heat so an aux heater with them is almost a must in really cold weather at low speed. But beyond 70 - 75 amp I would be worried about the main circuit looms, Most people when they start running wiring aren't thinking what 50,000 miles of vibration will do. 130 amps plus a battery could do a lot of damage if that extra wiring was not properly designed and protected. Buses also have another issue - it is almost 15' from the back, under the floor, up and to the dash. That leaves a lot of unprotected wiring. Certainly a modern master fuse box is needed near the battery with that much alternator amperage out there lurking.
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Last edited by SGKent on Mon Mar 20, 2023 6:45 pm; edited 1 time in total |
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raygreenwood
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Joined: November 24, 2008
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Location: Oklahoma City
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| Posted: Mon Mar 20, 2023 6:16 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| SGKent wrote: |
| Ray I agree with you in that accessories can add up. I ran a nice stereo in a 1971 bus with an amp, along with halogens and fogs - and never once over loaded the 38 amp generator in the bus. It might flare a little below 900 RPM. I can see where going to a 70 - 75 amp would be beneficial in cold weather when an aux heater is used. But, my brother Rick has type 3 that when I was done rebuilding the engine, putting new rubber ducts and boots in, you could cook someone out of that car in cold weather. Buses are larger and lots of uninsulated glass. Takes a lot of heat so an aux heater with them is almost a must in really cold weather at low speed. But beyond 70 - 75 amp I would be worried about the main circuit looms, Most people when they start running wiring aren't thinking what 50,000 miles of vibration will do. 130 amps plus a battery could do a lot of damage if that extra wiring was not properly designed and protected. Buses also have another issue - it is almost 15' from the back, under the floor, up and to the dash. That leaves a lot of unprotected wiring. Certainly a modern master fuse box is needed near the battery with that much alternator amperage out there lurking. |
See...I am not worried about the main wiring looms at all. I am not trying to pull more amps through anything than what they were designed to pull.
The headlights already have larger gauge wires. Actually they were set up from the factory to run 100 watt halogens if you measure the wire gauges on teh circuit and understand that they feed through a relay.
The difference in the 412 is that I have 4 headlights. They came factory with 55/65 low beam and 65 watt high beams. All four are on at one time. I upgraded them and they are 65/100 watt low beam and 100 high high beam...so 400 watts with high beams on....lovely throw too!
That alone is ~30-33 amps at 12 volts....actually if you can get 14.3 to them its about 28 amps.
Still....there are enough amps with everything running with the 55 amp...just barely. Its the cut in peaks that kill things when you are that close to the line.
The issue is that when you are say...low rpm and turning corners in wet night
winter weather......everything on, and you kick in the blinkers and your wipers slow down on every blink and you can see ever so slight dimming in teh headlights and hear the change in tone of either the dash fan or the heater booster turbocharger in the back.....at low rpm you are close to the wire in amps.
This is even without the big stereo yet...though it has a decent one in it. Not huge.
A lot of this problem is actually distribution within the vehicle and where everything pulls its power from. What's on each circuit.
One thing I am looking at that could help....is some very nice, inexpensive....voltage transformers. Technically they are rectifiers. They take 12-14v input and put out clean 12v with low ripple. The ones I am looking are about 1.5" x 4" x 8" in size, have limited adjustment/trimming and are very stable.
If I can get what I need I will post about them.
They have various amp output capability. I could easily see one feeding the EFI system, one feeding the fuel pump and ignition....or if enough amps...maybe one single unit feeding all three. Ray |
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vwwestyman
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Joined: April 24, 2004
Posts: 5688
Location: Manhattan, Kansas, USA
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| Posted: Tue Mar 21, 2023 7:24 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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Reading this with interest, as the alternator in my '73 is on it's last legs, I fear.
The light comes on when RPMs get a bit higher, and last couple times I drove it, I noticed that the RPM range of when the alternator cuts out (and light turns back on) is getting lower and lower over time.
That bus is running fuel injection, a BA6 and upgraded headlight bulbs (with relays) so I have also noticed over the past few winters that on short drives, the battery will get weaker, i.e. the alternator seems to have been struggling to charge the battery in cold weather driving, even before the current (no pun intended) issue.
One thing I don't fully understand is how the stock alternator interacts with the cooling fan... Is it simply that the alternator gets cooling air forced through it via the duct? Does the air flow front to back or back to front?
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raygreenwood
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Joined: November 24, 2008
Posts: 21519
Location: Oklahoma City
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| Posted: Tue Mar 21, 2023 11:22 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| vwwestyman wrote: |
Reading this with interest, as the alternator in my '73 is on it's last legs, I fear.
The light comes on when RPMs get a bit higher, and last couple times I drove it, I noticed that the RPM range of when the alternator cuts out (and light turns back on) is getting lower and lower over time.
That bus is running fuel injection, a BA6 and upgraded headlight bulbs (with relays) so I have also noticed over the past few winters that on short drives, the battery will get weaker, i.e. the alternator seems to have been struggling to charge the battery in cold weather driving, even before the current (no pun intended) issue.
One thing I don't fully understand is how the stock alternator interacts with the cooling fan... Is it simply that the alternator gets cooling air forced through it via the duct? Does the air flow front to back or back to front? |
This a great thread!
I agree with a lot of what SGKent is getting at. I fully agree that for virtually any bus and even my 412 car....with all the equipment running and if you have clean connectivity...the stock 55 amps is generally enough. However....even as hard as I work at it, these 40-50 year old vehicles will not have perfect connectivity. That eats some amps and volts. Then there is the non-stock equipment issue.
I also agree that if one could simply get the stepped up 70 amp alternator that would probably be all any of us require.
My point in answering the original question of this thread is not that "I" require 105 amps of theCS130....but that its one of those that has been worked with across many forums for classic cars. Readily available, high quality...and most importantly it has form factor/geometry that can be made to work.
The issue is that its not readily available at less than 105 amps....so the comments from metahacker about what it takes to absorb that much amperage are excellent.
Also, the comments from Wildthings about the successful use of the 10SI is also excellent. The 10SI and 12SI are also spoken of across many forums among people looking to do the same things we are with many different cars.
The most common 10SI I see is ~63 amps. The 12SI is ~94 amps.
There is also a good bit of studying up I need to do because there are a lot of issues and comments with regard to these alternators and whether they run hot or have short lifespans due to how they are connected, how the system is excited etc.
The more I look at the 10SI and 12SI the more I think they have better geometry and form factor than the CS130.
This is a good comparative page for the 10SI and 12SI
http://www.madelectrical.com/electricaltech/delcoremy.shtml
That page states that while the 10SI maxed at 63 amps....and the most common 12SI is 94 amps...the 12SI was also available in 56, 66, 78 and 94 amp models.
Supposedly the 10SI and the 12SI have the same size and general shape of case.
Depending on what the final amplifier ends up being for my stereo, I could get away with a 66 or 78 with no issues.
The other reason I do not want to keep the stock alternator with all of my set up (aside from it being hard to find a replacement for at any flaps)...is that is my slightly non stock car is pulling close to 50 amps when driving....its running close to its limit for long periods of time. That means HEAT.
Even when not using the heater in the summer....but travelling at highway speeds for long periods at night in places like Dallas, Houston, OKC etc....where the air temp is 90-100F at midnight....running with stereo and 400 watts of headlights plus injection, fuel pump and ignition....its pulling 40+ amps. And the cooling flow to the alternator is not really cool.
Years back travelling in these regions over a period of time I went through a couple of stock alternators. Baked windings. Still got good miles out of them...but they died from heat and they were no less cheap or easy to find in those days.
Here is a good excerpt from that page I linked to about the 10SI above:
| Quote: |
ABOUT HEAT WITH ALTERNATORS:
The significance of the previous heat calculations is that obviously when electrical power output is increased, the cooling capacity should also be increased. Otherwise, the situation is like installing a high performance big block V-8 engine, where a stock six cylinder used to be, and leaving the six cylinder radiator in place.
Therefore, 100amp output or 120amp rated alternators, built upon a 63amp 10SI case design are not always a good idea. If the application does not really need more than 63amps for very long periods of time, then the souped-up 10SI may live a long life. Also, sometimes the side effect of increasing the gross output rating is that we get increased output at idle and low RPM, which is good. If the application calls for considerable output at idle speed, but not especially a high gross output; then the souped-up 10SI may also live a long life.
Burned stator windings are common, in applications that continuously require a high amount of alternator output, and so are heat-damaged rectifiers. Some alternators are able to constantly put out a fairly high percentage of their gross output rating. Yet other designs fail when producing only about 50% of their gross output rating. For that reason, the author’s preference is always a good margin with cooling capacity per electrical power output. The models 10SI and 12SI alternators have proven to be very rugged with “stock” winding installed (output not greater than factory ratings). And for their cooling capacity, “stock’ model 10SI and 12SI GM Delco built alternators are favorites. |
Really a 63 or 66 amp 10SI or 12SI could be fine for me as the stereo will be running from the second battery.
Ray |
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aeromech
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Joined: January 24, 2006
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Location: San Diego, California
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| Posted: Tue Mar 21, 2023 11:37 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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How hard is it to fit this alternator Ray? Just installing a stock one is no cup of tee. Putting one in a T4 engine might be quite a bit more difficult that say a 49 Ford
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metahacker
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| Posted: Tue Mar 21, 2023 10:44 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| Quote: |
| One thing I am looking at that could help....is some very nice, inexpensive....voltage transformers. Technically they are rectifiers. They take 12-14v input and put out clean 12v with low ripple. The ones I am looking are about 1.5" x 4" x 8" in size, have limited adjustment/trimming and are very stable. |
I've had some fun with DC-DC units ... my Riviera came with a "thermoelectric" (peltier) refrigerator.. I tried my damnest to make it fit our needs...and keep the bus original. refurbed and resealed it, and even insulated it with NASA aerogel..... I put a 16V DC-DC on it... it helped ... but ultimately gave up and went to a compressor fridge (with the magical patented Danfoss Secop BD series compressor) ... best decision ever (and really kicked butt with the re-used aerogel)... but that 16V DC DC was fun
https://www.amazon.com/gp/product/B07JDD37Q2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
was only $26 and worked great ...
then i tried a 19V DC DC on my T4 heater booster fan ...
Well, that worked great ... until it didn't ;-) died on the end of our last big trip (San Diego -> Brooklyn NYC / Toronto Canada and back...and places in between) .. it was getting a lot of use .. but it kicked a lot of ass ... it may have been the aromatherapy essential oils i was absurdly feeding into it that may have killed it (was working fine for a long time daily driving until then)... but sure made the heater boxes smell nice ;-) try not to judge me...lol
shouldn't have been so greedy - if i stuck to the 16V im sure that fan would still be working :)
those things are fun. so cheap nowadays and epoxy encased / waterproof etc.
tempting to use it on more stuff
and yes ray i agree the 55a alt doesn't cut it at soon as anything fun is added - like an eberspacher or stereo with external amplifiers |
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raygreenwood
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Joined: November 24, 2008
Posts: 21519
Location: Oklahoma City
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| Posted: Tue Mar 21, 2023 11:23 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| metahacker wrote: |
| Quote: |
| One thing I am looking at that could help....is some very nice, inexpensive....voltage transformers. Technically they are rectifiers. They take 12-14v input and put out clean 12v with low ripple. The ones I am looking are about 1.5" x 4" x 8" in size, have limited adjustment/trimming and are very stable. |
I've had some fun with DC-DC units ... my Riviera came with a "thermoelectric" (peltier) refrigerator.. I tried my damnest to make it fit our needs...and keep the bus original. refurbed and resealed it, and even insulated it with NASA aerogel..... I put a 16V DC-DC on it... it helped ... but ultimately gave up and went to a compressor fridge (with the magical patented Danfoss Secop BD series compressor) ... best decision ever (and really kicked butt with the re-used aerogel)... but that 16V DC DC was fun
https://www.amazon.com/gp/product/B07JDD37Q2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
was only $26 and worked great ...
then i tried a 19V DC DC on my T4 heater booster fan ...
Well, that worked great ... until it didn't  died on the end of our last big trip (San Diego -> Brooklyn NYC / Toronto Canada and back...and places in between) .. it was getting a lot of use .. but it kicked a lot of ass ... it may have been the aromatherapy essential oils i was absurdly feeding into it that may have killed it (was working fine for a long time daily driving until then)... but sure made the heater boxes smell nice try not to judge me...lol
shouldn't have been so greedy - if i stuck to the 16V im sure that fan would still be working 
those things are fun. so cheap nowadays and epoxy encased / waterproof etc.
tempting to use it on more stuff
and yes ray i agree the 55a alt doesn't cut it at soon as anything fun is added - like an eberspacher or stereo with external amplifiers |
There are some really good Meanwell brand 12V DC to 12V DC or 14V DC to 12V transformers Iam looking at. Taiwan made. I have used numerous with LED applications. I will let you know what I find. Small, well heat sinked and affordable. Ray |
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chrmcc
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Location: Houston, TX
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| Posted: Sun Mar 26, 2023 2:14 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| In the end I found the current alternator only putting out ~12v. I replaced the stock 55amp alternator with a 70amp unit from eBay. While I was at it I replaced all of the wiring to/from the alternator and battery, cleaned any terminals and replaced the voltage regulator. I wish I had seen the post about the adjustable unit before I had ordered the Breu unit but it seems to be working fine. Now I have ~14v at the battery and at my aftermarket gauge on the dash. With my aftermarket AC fan on high it stays a little above 12v, before it would drop to 10v. I suspect I could see an improvement by replacing the wiring to the front of the bus and/or making a direct run to the battery for the fan motor but will call it good for now. Bigger fish to fry Here's the alternator I purchased: https://www.ebay.com/itm/254681086910 |
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aeromech
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Posts: 16971
Location: San Diego, California
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| Posted: Sun Mar 26, 2023 5:05 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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Crap! I need to go into the alternator business
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Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
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aeromech
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Joined: January 24, 2006
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Location: San Diego, California
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| Posted: Sun Mar 26, 2023 5:55 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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Crap! I need to go into the alternator business
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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vwwestyman
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Joined: April 24, 2004
Posts: 5688
Location: Manhattan, Kansas, USA
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| Posted: Mon Mar 27, 2023 1:00 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| chrmcc wrote: |
| In the end I found the current alternator only putting out ~12v. I replaced the stock 55amp alternator with a 70amp unit from eBay. While I was at it I replaced all of the wiring to/from the alternator and battery, cleaned any terminals and replaced the voltage regulator. I wish I had seen the post about the adjustable unit before I had ordered the Breu unit but it seems to be working fine. Now I have ~14v at the battery and at my aftermarket gauge on the dash. With my aftermarket AC fan on high it stays a little above 12v, before it would drop to 10v. I suspect I could see an improvement by replacing the wiring to the front of the bus and/or making a direct run to the battery for the fan motor but will call it good for now. Bigger fish to fry Here's the alternator I purchased: https://www.ebay.com/itm/254681086910 |
Which air boot does that alternator take?
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President, Wild Westerner Club
1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
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chrmcc
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Joined: April 29, 2022
Posts: 24
Location: Houston, TX
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| Posted: Mon Apr 03, 2023 3:09 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| vwwestyman wrote: |
| chrmcc wrote: |
| In the end I found the current alternator only putting out ~12v. I replaced the stock 55amp alternator with a 70amp unit from eBay. While I was at it I replaced all of the wiring to/from the alternator and battery, cleaned any terminals and replaced the voltage regulator. I wish I had seen the post about the adjustable unit before I had ordered the Breu unit but it seems to be working fine. Now I have ~14v at the battery and at my aftermarket gauge on the dash. With my aftermarket AC fan on high it stays a little above 12v, before it would drop to 10v. I suspect I could see an improvement by replacing the wiring to the front of the bus and/or making a direct run to the battery for the fan motor but will call it good for now. Bigger fish to fry Here's the alternator I purchased: https://www.ebay.com/itm/254681086910 |
Which air boot does that alternator take? |
The round one, I bought a new boot here: https://www.ebay.com/itm/384908008184 |
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vwwestyman
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vwwestyman
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| Posted: Mon Apr 10, 2023 6:33 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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Another question for everyone:
My issue is that as I'm driving and the RPMs get higher, the alternator and brake lights come on, and the alternator stops charging. (Verified the last part by hooking a tester up, and watching the voltage suddenly drop when the lights come on.)
Before I spend a bunch of money on another alternator, is there anything else that could be causing the problem?
Last fall, I did go through and clean all the battery cables and grounds I could find, and I added a ground from the fan shroud to the battery. This didn't really make a difference.
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Wildthings
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| Posted: Mon Apr 10, 2023 8:17 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| As a guess I am going to say your brushes are worn out and as the alternator gets hot they no longer touch the slip rings on the rotor. |
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vwwestyman
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Location: Manhattan, Kansas, USA
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| Posted: Mon Apr 10, 2023 4:46 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| Wildthings wrote: |
| As a guess I am going to say your brushes are worn out and as the alternator gets hot they no longer touch the slip rings on the rotor. |
It is pretty consistent with RPMs, regardless of how long the engine has been running, whether it is warm or cold out or whatever.
What I'm trying to ascertain is whether there could be some other issue that could cause this-that if I replaced the alternator, is there any chance it is something else and I'd have the same problem?
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Dave Cook
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Wildthings
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| Posted: Mon Apr 10, 2023 4:54 pm Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| vwwestyman wrote: |
| Wildthings wrote: |
| As a guess I am going to say your brushes are worn out and as the alternator gets hot they no longer touch the slip rings on the rotor. |
It is pretty consistent with RPMs, regardless of how long the engine has been running, whether it is warm or cold out or whatever.
What I'm trying to ascertain is whether there could be some other issue that could cause this-that if I replaced the alternator, is there any chance it is something else and I'd have the same problem? |
The alternator isn't going to un-excite over a wiring problem short of a dead short, so a wiring problem would show itself with a lot of smoke. I would still tend to say worn brushes as maybe the vibrations at a certain rpm cause them to lose contact with the slip ring.
Could always be wrong though.  |
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vwwestyman
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Location: Manhattan, Kansas, USA
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| Posted: Tue Apr 11, 2023 4:58 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| Wildthings wrote: |
| vwwestyman wrote: |
| Wildthings wrote: |
| As a guess I am going to say your brushes are worn out and as the alternator gets hot they no longer touch the slip rings on the rotor. |
It is pretty consistent with RPMs, regardless of how long the engine has been running, whether it is warm or cold out or whatever.
What I'm trying to ascertain is whether there could be some other issue that could cause this-that if I replaced the alternator, is there any chance it is something else and I'd have the same problem? |
The alternator isn't going to un-excite over a wiring problem short of a dead short, so a wiring problem would show itself with a lot of smoke. I would still tend to say worn brushes as maybe the vibrations at a certain rpm cause them to lose contact with the slip ring.
Could always be wrong though. |
Certainly that logic is sound.
One potential confound...?
I have observed that with the RPMs up high enough that the light glows, turning on the headlights, even to high beam (and I have high wattage bulbs in there) or turning on the BA6 doesn't seem to have any effect on the glowing. Same with turn signals, wipers, radio, etc.
However, if I slide the heat lever all the way down such that the above-engine booster fan comes on, the light does glow brighter.
Note that my BA6 is installed in a '73 and so it seemed that the wiring was ever so slightly different than later Buses. So the BA6 will run perfectly fine in this bus, even if the heater lever is all the way off, and therefore will run without the engine booster fan running. Seems like I had read that in factory '75 and up installations, the heater lever had to be far enough down to activate the booster fan.
I have the day off tomorrow, so I can investigate this further if anyone has any thoughts as to why this might be.
Or could it just be that the booster fan draws so much current that it is enough to draw the battery down enough to make the light glow brighter, whereas the other consumers don't?
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1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
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Wildthings
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| Posted: Tue Apr 11, 2023 9:16 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| You are beyond what I know about alternators. It sure sounds like the current through you field coil is dropping out for whatever reason. Brushes, small diode trio, maybe something internal to the regulator, possibly the green wire between the regulator and alternator has a break, maybe a ground issue for the regulator? I guess if the brown wire has an issue and the regulator has no other ground that could be it. |
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vwwestyman
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| Posted: Thu Apr 13, 2023 6:29 am Post subject: Re: 78 Bus w/T4 FI - Alternator Alternatives |
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| vwwestyman wrote: |
I'm thinking this might be my option.
Couple questions:
You said you ran it for a while... Why did you stop running it? Did it go bad or you sell the bus or something else? |
Went ahead and just ordered this. Also ordered one of those adjustable voltage regulators.
We shall see how it works!
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Dave Cook
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1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
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