'87 Westy Air Conditioning Fan Speed

[Wanderingman]

Westy Noobie - first post. I purchased my 1st Westy(also 1st VW) two weeks ago. Overall, she's in great shape and functions well. I had the A/C system(still R12) charged up yesterday and it's blowing ice cold. Not to complain, but it's blowing too cold since the fan speed switch will only work on setting 4 blowing at max. speed. I've searched the forum to find out the potential issue, but it seems everybody is saying their switch doesn't work at all. Can anyone shed some light on this for me or send me an existing link/post that I may have overlooked? Is it the switch in the dash or something in the rear pillar...or elsewhere? I enjoy tinkering, but I've never been much of an electrician! Thanks for the help!
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'87 Westy, 2.1L Stock Engine, 4-Speed Manual

[campism]

This thread may help. At least it involves one speed so may lead you in your troubleshooting. Good luck! '87 Westies are the best.

http://www.thesamba.com/vw/forum/viewtopic.php?t=556394
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'87 Westy in Wolfram Grey Metallic

[Howesight]

If you look at the wiring diagram in the Bentley manual (page 97.140), you will see that the AC blower fan features a resistors for speeds 1 through 3 and for high speed, the blower switch connects to a relay that passes the full 12 volts to the blower fan. For speed 3, the AC relay provides power to the resistors. Your symptoms seem to indicate that the blower resistors is faulty or the switch is faulty. The likelihood of two resistors both failing seems low, so the switch may be the culprit. Remove it, disconnect the connector, and jumper the terminal with the green and black wire to the terminal with the black and white wire. You should now have low speed. If so, the switch is now proven bad. If not, the resistors are the problem and you have to remove the whole AC cabinet to access them for replacement.
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'86 Syncro Westy SVX

[Wanderingman]

Awesome! I appreciate the speedy replies and steering toward how to troubleshoot it. It will be sometime next week before I can get to it, but I'll be sure to post the outcome. THANKS!
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'87 Westy, 2.1L Stock Engine, 4-Speed Manual

[markz2004]

Be VERY careful with the switch. They are not easy to find replacements if it is broken or broken while trying to fix.

I was trying to fix mine and surely it is now broken. I was lucky in finding a replacement.
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87 Westy, 250k GW 2.4 - 2.0 , 16" wheels

[Wanderingman]

[denwood]

Note the relays in the back of the van and speeds 1 and 2 "powered" from the switch vs 3rd and fourth. Once the switch is tested ok, time to start with the relays in the rear cabinet. Two resistors gone bad for both rear AC fans I'd agree sounds unlikely.

[Wanderingman]

Well, I finally got around to testing everything(with the exception of the resistors themselves), but I guess it's been narrowed down to them...unfortunately. I am not looking forward to removing the A/C evaporator housing, etc, after looking it over today. This actually leads me to my next question. Where do I start when removing it and how involved is it? I know others have indicated is not a fun job, but I haven't been able to find a complete description of what needs to be removed and how? Have I overlooked it somewhere on here or in Bentley's?

Thanks again to you guys who provided the great direction on troubleshooting the problem.
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'87 Westy, 2.1L Stock Engine, 4-Speed Manual

[CessnaJon]

Don't miss the Vanagon get-together at the Varsity next Thursday (11th)! Lots of folks to lend a hand there.
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1973 Westy (shared birthday)
1990 Westy Multivan
2015 Passat TDI 6sp
2015 Sportwagon TDI 6sp
LR-JET, Gulfstream 159

[denwood]

It's not a difficult job, but lots of screws to pull if your van has the front plenum setup.

For the plenum, I had to remove some trim pieces at the front of the bed and side rail (mine has a storage cubby blocking access to some screws) however all the screws that are visible need to be removed, then four more hiding up under the upper mattress cover. Pull plenum forward slightly to disengage it from the groove routed in the condenser cover.

Two bolts are now visible that you can remove (condenser housing). One bolt goes through the closet, another behind it in the upper left hatch area. Remove the rear condenser screen (two screws). The last two bolts visible (accessible from bottom of condenser housing) will drop the evap housing. You should support it, or have a buddy on hand to help.

Putting it back, a few tips to make life easier:

AC Plenum mods to improve air flow and quiet things down:
http://www.thesamba.com/vw/forum/viewtopic.php?t=4...;start=160

A few tricks with a router to make reinstallation much, much easier..and make solid connections to the condensate tray with new drain tubes.
http://www.thesamba.com/vw/forum/viewtopic.php?t=2...;start=560
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Cheers,
Dennis Wood
The Grape

[morymob]

The t-stat must not be working, i adj to my comfort level and go but i do see a need 4 slower fan.

[Wanderingman]

[Wanderingman]

So I FINALLY got around to starting on the A/C evaporator disassembly today. Yes, I've been procrastinating. Anyway, after getting all taken apart and testing the resistors, THEY ARE FINE! I then went back to checking the switch(which I knew as good because it's a new one), the rheostat/thermostat switch(it was good too) and then the relays again. The funny thing is this time around all the fan speeds were functioning except number three, whereas before only number four was working. Weird. Anyway, based on the current status it appears I will be replacing the A/C relay(171959141A).

As I had mentioned previously, the last time I had the A/C running I ended up starting a waterfall out of the evaporator. The drain hoses are plugged, right? Wrong. I blew through them while they were still connected to the drain pain. No obstructions. Furthermore, no cracks in the drain pain. Now I'm at a loss as to where to look next. Any other ideas out there from you ol' pros?
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'87 Westy, 2.1L Stock Engine, 4-Speed Manual

[denwood]

Pour some water in the pan, installed. See what happens

The plastic nipple on the pan where the hoses connect may be cracked. One of mine was. A good reason to route the vertical "drain hose" channels in the evap housing and attach the drain pan directly to the evaporator is simply to ensure there are no leaks, before you go through all the hassle of reinstalling.

The AC relay and 3rd fan speed fail is exactly the issue that I had. The AC relay also fires up the rad fan on low speed, so if both rad fan and AC 3rd speed are pooched, good chance AC relay is done. If the AC fan switch has issues with power supply (1st, and 2nd) speed, and the AC relay was wonky, you would only end up with 4th speed. My setup with the evap/plenum mods etc. is freezing my wife in the front seat at 2nd speed. Haven't used 3rd or 4th yet.
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Cheers,
Dennis Wood
The Grape

[Wanderingman]

I am definitely doing the housing drain hose channels. Regarding the attachment of the drain pain with zip ties, does the evaporator HAVE to be dropped to do it? I looked at it yesterday and I couldn't find any space to run the zip ties around the top? I am not disconnecting my system since I just got it charged up a couple of weeks ago, but I guess the evap could be lowered enough without disconnecting the hoses in order to install the zip ties???

Regarding the fan speeds and power supply, I had tested the relays previously and they all worked fine. My radiator fan also works fine(all the time). I have ordered a new relay, but is there something I can do about the power supply issue(which must be the problem), short of installing a new alternator?

I also started applying sound deadener yesterday. Got the blowers done. Do you see any benefit of doing anything further on the evap housing and/or plenum besides the way you did the speaker boxes?

Thanks for your great posts!
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'87 Westy, 2.1L Stock Engine, 4-Speed Manual

[denwood]

As far as power supply, what I meant is to confirm that power to the switch (1st and 2nd speeds) is good, and grounds there good as well.

If you check out page 3: http://www.lakoautoklub.hu/archivum/letoltes/tartalom/van_4_89.pdf you can see that the AC thermostat (switch) provides power to the Evap fan switch to power speeds 1 and 2. The switch and AC thermostat functions (separate on the schematic) are both provided by the AC thermostat knob/switch assembly.

You don't have to disconnect the evaporator to drop it a bit and sneak the ties over top...just support it when you remove the two bolts attaching it to the two hangars. It normally sits snug against the top plastic shroud which if I recall is part of the evap fan shroud housing. As far as any further tweaks..I don't see much benefit. The dynamat etc. just provides a bit of thermal insulation and more importantly stops any resonance in the assemblies. On 2nd speed the AC is nearly silent to front passengers at 30mph, and on 3rd, just audible up front. My kids had zero complaints in the back seat. With the AC working as well as it does, removing the plenum would likely freeze the little monkeys...I have the two vents over them closed.

As far as my tweaks for the evap fans etc., there was nothing obvious more that I would do...very happy with the AC now. With respect to the posts..my pleasure. I've picked up a lot here on the forum so feel a bit of responsiblity to help out when I feel there is a contribution to make

Cheers,
Dennis.
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Cheers,
Dennis Wood
The Grape

[All4You]

Hello

Can someone please confirm that A/C relay (171959141A) is indeed what causes setting 3 failure? In mine, setting 1,2, and 4 work but not 3.

Thanks in advance

All4Him
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86' Syncro, EJ25
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Build Thread
http://www.thesamba.com/vw/forum/viewtopic.php?t=647477&postdays=0&postorder=asc&start=0

[crazyvwvanman]

The A/C relay is the most likely cause if only speed 3 is missing on the 86+ system.

Mark

[All4You]

Thanks
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86' Syncro, EJ25
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Build Thread
http://www.thesamba.com/vw/forum/viewtopic.php?t=647477&postdays=0&postorder=asc&start=0

[All4You]

YES! New relay fixed the 3rd setting. It's so satisfying when the fix is simple and works on the first try and without causing other things to break. Now let's see if I can get my AC to blow cold air.

All4Him
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86' Syncro, EJ25
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Build Thread
http://www.thesamba.com/vw/forum/viewtopic.php?t=647477&postdays=0&postorder=asc&start=0