| Author |
Message |
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
 Posted: Sat Jul 17, 2021 3:35 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
 |
|
Well .........
Funny thing.
That Bentley Wiring Diagram for the Blower fans?
Yeah...... that ain't right!
Main power feed into the switch?
Bentley says .......Green/Black
Real World says ...... Black
Fan Speed 1 ?
Bentley says ........Black/White
Real World says ..... White/Black
Fan Speed 2 ?
Bentley says ....... Black/Green
Real World says ..... Black/Green
Fan Speed 3 ?
Bentley Says ........ White
Real World says ...... White
Fan Speed 4 ?
Bentley says .......Yellow
Real World says ...... Yellow
So it isn't ALL incorrect but enough.
I jumped from the Black Power + wire to each wire at the speed switch plug.
I have every speed at the correct place.
Conclusion?
Switch is buggered.
Anticipated repair?
New Switch (or good used)
I wonder if this mixing of speeds within the fan switch may have overheated/ backfed the high speed relay causing the fire?
I want to ohm this switch and see where the power is going out rather than where it should go.
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
 |
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sat Jul 17, 2021 7:32 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
| Sounds like a good fan plan. Check the lines for voltage drop under load too to see if there is a connector or corroded wire issue. |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sun Jul 18, 2021 6:24 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Nice clean contacts. Any jumper results for the switch?
The more I think about it, I will put my resistors behind the PS headlight. All 4 speeds will be relayed right there and so a single 10 gauge wire needs to go back and feed the fans. Very little switch load on speeds 1 and 2. A separate 50 amp circuit breaker at the start battery directly to the relays. No long relay coil trigger wires. And NO connectors in the middle of the wires. If it works for the headlights, why can't it work for the fans? Both are big draw items.
And why do the fans have fuses on the ground path? Headlights don't. |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
| Posted: Sun Jul 18, 2021 10:34 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Let's start at the end.
62° inside air
59° interior objects
42° exiting plenum.
It wasn't without its trials and stress!
It started out good, the system right off the bat readily sucked in a can of Redtek r12a.
Great!
But no joy at the pressure switch.
It should close and engage the A/C clutch with a can in, but it didn't.
No biggie, I jumped 12v to the clutch, "click! And off it went!
Even the idle speed increase worked! Life is good!
I had just tapped on the 3rd can and was about 1/2 through it when I noticed hissing and an oily drip at the pressure switch!
Oh Crap!
It held vacuum just fine but can't handle pressure?
For sure!
The modified VW switch literally exploded open!
The oil loss was minor but the gas? I've no clue what I lost.
Atmospheric air never got in, it was still spewing as I unscrewed it and the Schrader valve cut off the bleeding!
Then I looked up and saw a White Van pull away from my mailbox...... couldn't be....... but there it was! ........ my universal pressure switch arrived in the most timely manner!
Anyway I guessed at how much Redtek I put in by pressures and plenum temperatures.
It isn't a hot day so I will tweak the charge as the hot days return.
I absolutely FROZE on my test drive!
I'm used to 90+° degree days and it was 62° in the Van!
I was wishing for a sweat shirt.
I have the blower fan hot wired to speed 3, there was no speed adjustment except by unplugging and moving the wire.
Pictures to come, lunch time.
I do have a new rattle with the Evaporator assembly in place.
I'll chase that down and mitigate it but now is clean up and reorganize time!
You do notice the power drag on my 90 horses, but not sweltering as you drive will be entirely worth the power loss!
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sun Jul 18, 2021 1:53 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Congratulations A job 90% well done and the other 10 percenters are like all Vanagon issues. You will get to 98% and then that's as far as we can go, but usually it's close enough.
Thanks for the wire color tip. Have already marked the pages.
Froze your butt off in July. Now that's incentive for me to get goin' on mine.
Duncan |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
| Posted: Sun Jul 18, 2021 6:19 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
It took a bit of thinking and tracing wires to get things working.
The wiring colors for the pressure switch aren't 100% what the Bentley shows!
The VW pressure switch did NOT like my modification!
It held vacuum just fine.
But once you put high pressure to it?
It literally blew apart!
The new switch is a universal female mount pressure switch.
It came with zero supporting documents and Goggling it produced little more.
I used my ohm meter to determine how to hook up the switch.
The High/Low portion should always be open under normal pressure.
The clutch engage portion should be closed during normal operation.
I ended up clipping off the plug from the VW switch and splicing it on to the universal switch.
The black wires on the universal switch are the compressor clutch and connected to the blue of the VW switch.
The blue wires of the universal switch are the High/Low and connected to the Red of the VW switch.
Once charged I disconnected the gauges and ran out to get a late lunch.
Here is the temperature of the horn pad 57.3° .......
I installed the right D pillar trim!
It Looks great!
Tomorrow is forecast to be well into the 80's...... let's see how the A/C does.
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sun Jul 18, 2021 6:55 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
| Super great and thanks for the masters class tutorial |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Mon Jul 19, 2021 4:08 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
| Can you tell which components are creating the heat? I wonder if it would be possible to mount them to the D pillar metal is such a way for it to act like a heat sink and dissipate some of the heat to the duct and outside the envelope. |
|
| Back to top |
|
|
Abscate
Samba Member
Joined: October 05, 2014
Posts: 22639
Location: NYC/Upstate/ROW
|
| Posted: Mon Jul 19, 2021 7:26 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
You want HNBR Orings throughout.
Green is usually indicative but not perfectly so.
Not spending the time to spec the right ones which cost pennies each, vs a $150 evacuate charge cost, is crazy.
_________________
.ssS! |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
dgbeatty
Samba Member
Joined: October 26, 2006
Posts: 702
Location: Sacramento
|
| Posted: Mon Jul 19, 2021 11:02 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Dave
Same ole song. Move the radiator fan load to the dash with an additional relay re: SA design. Have you replaced the strip fuse with a MIDI fuse? Did you increase the wire sizes to 6mm²? These changes will greatly reduce the heat.
I have additional electronics in this area and thus have a 40mm temp controlled fan. Just because as an engineer I can clearly see the unmet need (bean counter effect).
_________________
Schau in das Buch |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32574
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
dgbeatty
Samba Member
Joined: October 26, 2006
Posts: 702
Location: Sacramento
|
| Posted: Mon Jul 19, 2021 2:58 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
The front switch is another area that deserves two relays be added (in the rear). The first 2 speeds put an unacceptable load on the switch and loong wiring. The wiring commonly fails ie melts, shortly after the second OE switch has been replaced and the blowers are no longer new. Again see the SA redesign.
_________________
Schau in das Buch |
|
| Back to top |
|
|
|
