Question Ratwell voltage reg check & my issues

[mr matt]

History
77 FI camper.

Removed positive batt cable before pulling engine. Put engine back in , now getting alternator and EGR light on dash. (Always did pos cable in doing bugs, and winter storage.. even the bus).

Removing engine requires removing wired plugs etc

Here is Ratwells voltage reg check

As for ratwells chart, - 1st of all, why would there not be 12 volts always at the blue-red wire when the ignition key is in the on positon? The blue wire is having 12 volts as it comes from the dash





From my blue wire I have a black wire connected to it.
When I have the key on I get a voltage reading at the D+ plug ( blue/red) of less than 1 volt. If I disconnect the black wire I get 12 volts

This black wire ( which can be disconnected) goes from the plug into a sheath toward the battery then up, up across the hatch and down the inside of the left hatch to a small relay. ( not sure what relay this is yet).

( In this same sheath, also noticed a red wire going from the NEG battery post to the same relay)

I know the wires from the volt regulator go into a sheath down to the alternator. From this sheath I also see a black wire that is not hooked to anything ( part of which can be seen @ about 9:30 in the photo.

I also include a "drawn" diagram showing my wire situation.

I just dont get why I would be getting my alt light on (and EGR) - the only thing I did to the alternator was to move it to remove and install the belt so as to check for endplay when engine was out

Any input or thoughts would be helpful. Learning, ... but still need to learn a lot about buses.

Thanks
Matt

Also as Ratwell is expecting to see 1.28V at the R/B wire plug, I am hesitant to leave my black wire disconnnected and let that plug see 12 volts from the blue wire.. and plugging it back in into the volt regulator.
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[Wildthings]

[timvw7476]

I've got no answers to your technical question(s), but when my battery light is
on & won't go off when running, it tends to be time to check all the leads
going into the voltage regulator, reach under there & seat each wire, that
old plastic block lets them wiggle about & sometimes they don't all seat
even though you've plugged it in. Next step is clean the battery posts if that
doesn't put the charge light out.

[busdaddy]

12v on a disconnected blue wire is normal, connect it to the red wire and it'll drop to around where Ratwell specifies (and the dash light will illuminate), the resistance of the idiot light filament creates the drop.
The black wire coming from the alternator harness was for the test network, tape it up since it's constant 12V and unfused.
That harness leading across to the house battery relay has some oddly colored wires in it, you'll have to determine which terminals what color is on at the relay before we can advise where to connect what.
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[mr matt]

Thank you all for taking the time to respond...
Thanks Tim, I double checked the contacts!

Wild, .. never knew that... thanks will go for the neg cable 1st in the future.


BusDaddy

As for the colors of the wires to plug designation, it is as follows

From the plug to the voltage relay:
Brown is D-
Green is DF
and Red/Blu is D+

The black wire which comes off the blue wire goes to the back left of the bus to a relay. As I was confirming this is the same black wire with an OHM meter, while the black wire was off the little relay, I cleaned the prong of the relay. Now with the ignition on I test the R/B wire at the plug, instead of getting a small voltage, now I am getting 7.10 volts (!)


Wondering if I plug the plug back in the relay, with that much voltage - wonder if I will burn something out. This is crazy.

I am not so good at reading the schematics, I cannot locate the relay or multiprong unit that is just inside, down to the left of the engine bay door.

I do not see any schematic showing a lead coming off the negative battery post at all, let alone going to the above mentioned relay.

Sorry to sound frustrated, but I am!

Thanks
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[Wildthings]

What someone did is use the D+ circuit to trigger a relay. This will keep the electrical load low during cranking and until the alternator energizes. Not a bad system, but it can cause you to need to rev the engine a bit to get the alternator to energize.

[busdaddy]

[Tcash]

Is this the relay?

[mr matt]

Wish I did not have to work long hours!

I was thinking about this today, I know talking about wiring is not so exciting as many other things to address on bus related threads, so I want to say thanks so much to all of you for keeping up with me on this. It really surprises me there are people who want to be so helpful. I know this takes time from other things your could be doing.. Thanks!

OK, this is what I found.


I think what TCash was showing is correct..

Placement ( just inside left to the engine hatch)

diagram

Hookups

Drawn info found on relay and schematic

Not sure if " [ " are C's or E's - too worn to tell

Ok, so from my drawing;

#30 red wire which goes into the sheath goes to the NEGATIVE post on my main battery

#86 black wire which goes to the same above sheath goes all the way up and connects to the blue wire at the voltage relay. Does this make sense?

#87 Thick red wire goes to POSITIVE on aux battery

I see TCash ahs #30 wire going to positive terminal on main battery while mine is negative. (!!)


I know if I disconnect the #86 black wire, I believe the alternator dash light goes out... not real sure, would have to double check

what purpose does this relay (if that is a correct term) serve?

Oh wait, I was looking at the schematic on the relay... so this relay allows charging to the auxiliary battery via the main battery? That is my guess. If correct, just wonder why the black wire would "bother" to be joined to the blue wire... oh, so the voltage regulator would somehow tie into the action of the auxiliary battery charging?

Matt
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[telford dorr]

The relay is used to charge the aux battery. When the alternator generates enough voltage at the D+ terminal (which only can occur once the engine is running), power travels from D+ down the black wire through the relay coil (86), then to ground (85), causing the relay to close. This connects the main battery (30) to the aux battery (87), allowing the alternator to charge both. This way, the possibly discharged aux battery is isolated from the main battery until the engine is started and running.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Wildthings]

[mr matt]

Thanks Telford,

That completes the picture in my head.


Wild, yes I cannot understand why the #30 wire is going to the ground of the main battery - what is with that... however it seemed to be working.. nevertheless, I am going to change it over to the positive terminal on the battery. When I saw a red cable coming off the negative terminal - I thought that did not look right.


Once I change it over, I will again check the volt relay plug voltage with the ignition on and see what I get.


It still seems strange when I put the engine back in, I had both the alternator light come on, AND the EGR... made me wonder if there is a common line between them that is an issue.

Thanks
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[busdaddy]

[Wildthings]

[telford dorr]

X2 ^^^

Go one better: ignore the wire color and connect it to the correctly labeled battery terminal, etc. Once you get it working, either replace the cables with the correct color, or get a package of colored electrical tapes at Home Depot, and wrap the cable ends with the correct color tape. Might even get some colored model paint and paint the tops of the battery posts with the appropriate color.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[mr matt]

Thanks again,
I woke up early trying to go back to sleep, but this wiring was stuck in my head.

What really gets me, is for the month I had this bus, and on occasion drive it, there were no EGR and Alt lights coming on (permanently) at all, and batteries seemed to be accepting a charge. Left interior light on once over the sink, and I think that drained the aux battery, but running the bus around charged it back up.

Taking the engine out ( which requires removing relay plug) and putting it back in made both EGR and ALT light stay on permanently.

I did however move the alt a few times to take belt off & on, so wonder if cables came undone or something underneath.


Nevertheless...

Here is an easier for me to read schematic I found showing the aux battery.

This morning I was thinking I don't get why it is wired the way it is and how it could charge the main battery, and I don't get how it was doing it.


I appreciate your comments,

I am not sure I can get current through the aux relay as I am not apparently getting voltage from the alternator either by bad alt, bad Volt regulator or this bad wiring.

so what I understand is that once the voltage passes through the voltage regulator it is through aux relay my my main battery is charged - in through 86 out through 30. This charge is governed not by the aux relay but upstream by the volt regulator. If the volt regulator says to charge the main battery, it does through the aux battery. IF this is true than the big red wire out from #30 for me is going to the negative post (!) I will confirm this as suggested. I will disconnect both ends of this wire and verify by OHM that this is a isolated single wire. I know without a doubt this red wire is on the negative post of my battery. The ground strap is also there. My volt meter confirms neg vs positive.

Wild, this is where I will put in your idea; from the #30 terminal I will put my volt meter, positive lead to #30, black lead to ground. and hope to get a signal.
Looking at my diagram above, I think I am wrong, it seems the black wire is always supplying 12V(?) to the aux relay, and a switch there will charge my battery when relay closes (??) If so, then what in the world is the voltage regulator doing to charge my battery...? Seems like it is not needed. I am missing something.

I will also remove #87 lead which goes to the aux battery - just to be safer.. or will this not have the relay work as it should...?

Yes, I am paranoid about causing a fire...
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[Wildthings]

The blue wire sees 12+ volts once the alternator energizes (turns on). It is not the regulator that does this but the alternator and then once the blue wire has 12+ volts on it the relay is triggered.

[mr matt]

OK this is what I did...

I disconnected the red wire; one end from terminal #30 and other end from the negative post of main battery. I confirmed this wire is not connected to anything else and is continuous.

Coming from the same sheath, I disconnected the black wire ; one end from terminal 86, the other from the joining the blue wire near voltage reg. confirmed this wire is not connected to anything else and is continuous.

I hooked up both ends of the black wire.
I hooked up one end of the red wire to #30, the other end was to my voltmeter.
With the ignition off, volts = 0
With ignition on(engine not starting) volts = 0.02
With ignition on, Alt and EGR light on.


I started the engine Both Alternator and EGR light went off!
My main battery was charging at 13.5V 1st time since the engine went back in!

My voltmeter being connected to red wire going to terminal 30 showed an initial voltage of 0.2 but was climbing. after 10 minutes it was over 1 volt.

I was sure that my aux battery was not receiving a charge, but just to be sure no craziness was going on, I tested it - showed only 12.5V

So I think this is progress... I like my battery charging...

I have not done it yet, but I think it would be safe to connect the wire from terminal #30 to my positive post on my main battery, instead of the negative post - unless someone sees something I don't and advises otherwise.... is this correct?

strange how the EGR light also went out.
_________________
1955 3-fold semaphore Oval beetle
1971 Convertible beetle
1977 Westfalia, FI, Berlin interior

[Wildthings]

As I said in a post above, if the wire to the #30 terminal was once connected to the negative battery terminal then the relay is probably toast. Had the rely ever been activated with the wires hooked up this way its life would have been measured in milliseconds.

[telford dorr]