A/C temperature control

[snuf]

Last fall I had gotten A/C up and running on my 86 Wolfsberg Weekender, but had to put a jumper between the red and green wire to get it to kick in. Checked the refrigerant today and it is still holding pressure.
Since the warmer weather is approaching and I will be using it more, I would like to know if it is advisable to continue to operate with the jumper wire. I believe that the purpose of the control is to shut off A/C if temp gets below a certain point.
If I should replace it, does any one know where to get one or an alternate part.
There is no VW Part No. on it, only the following:
GENELCO
14-955S
6539 (28)F

Any and all advise is appreciated.
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1986 Wolfsberg Limited Edition Vanagon.
AKA: Poptop with rear corner cabinet, fold down side table, rear-facing jump seat and a 12v fridge/cooler.

[Terry Kay]

Not sure what you have pictured here under the dash.

The AC controls & the temp kick out switch is on the Left Hand D pillar in back of the Van in 86--not under the dash by the fuse box cover.
_________________
T.K.

[snuf]

It has something to do with controlling the temperature, as the two yellow wires come from the switch on the dash. This is the type of switch that I have:
http://www.gowesty.com/ec_view_details.php?id=4065&category_id=304&category_parent_id=
(if you scroll down, you can see where they attach to switch)
Most likely The A/C system I have is the early type. 85-86 were crossover years.

I did look at the D-Pillar while servicing A/C and the only things I found there were two hoses and the wiring harness. Jumping the wires was the only way I could get the compresser to kick in.
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1986 Wolfsberg Limited Edition Vanagon.
AKA: Poptop with rear corner cabinet, fold down side table, rear-facing jump seat and a 12v fridge/cooler.

[Terry Kay]

I see what you saying now---
You've elminated the dash temp control switch.

No big deal.

The compressor kicks on right now, and stays wide open when the AC is turned on.

The inerior temp switch I was thinking about shuts the system down when the interior reaches the slected temp on that control switch.

You won't do any harm running it the way you are--
Most folks crank that knob all the way open anyway, you've just eliminated having to twist the switch.
_________________
T.K.

[Dogpilot]

Here is the link for the replacement part:
http://www.gowesty.com/ec_view_details.php?id=4065&category_id=&category_parent_id=

It used to be very hard to find and GoWesty has found one that works and is offering it at a reasonable price.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[turbo2cv]

I have a 1985 Vanagon with pop-top and factory A/C.
Lucas at GoWesty says 84-86 Vanagons have the same AC setup. http://www.gowesty.com/library_article.php?id=311

That explains why i see the same part in my Vanagon as snuf.

Inside the black plastic box with 14-955S and 0739 28(5)F written on it is a small electronic board with a relay and a few other components. On the back of the board it is printed B14 995 03B and TCI-AnS 94V-0. The relay has 111C D012-K F SW5 written on it.

I believe when the rotary temp control switch provides continuity between the yellow wires, this board should keep the compressor engaged. Not sure if there are other conditions this board looks at. I believe this is snuf's concern as well. Jumping the red and green may hide the true issue in the A/C system.

On my van the relay on that board occasionally behaves fine (compressor runs or stops for a decent amount of time) and other times it keeps toggling between open and closed fairly fast. The toggling happens 5-10 times in a second. As a result the compressor's clutch keeps engaging and releasing. It does not sound right.

All three speeds work on the evaporator fan, the condenser cooling fan runs when the evaporator fan is on (I believe the condenser fan keeps running even when compressor is off). When the compressor runs the AC makes cold air. It is a red-tek conversion including one can of proseal.

I am pretty sure the issue is with this board and not the rotary temp control switch: I jumped the yellow wires and toggling keeps happening. Jumping yellow wires is equivalent to temp control saying : max cold. I don't know how to fix it. Please shed some light on this.

My Bentley (1991 version) on page 87.2 states "from 1986", but I believe it should be up to 1986. Regardless, Bentley does not seem to cover my van's AC in much detail. On page 97.138 it shows a/c compressor cut out relay, but no electronic components.

Here is that board

[MarkWard]

I am not familiar with that part. Two minor points. The compressor needs to cycle to keep the evaporator from icing up. A thermostat of some type controls the evap temp. Not sure about this earlier AC, but a cycling clutch can indicate a low charge of Freon. Some ac systems are fitted with pressure switches to prevent damage from running on low Freon. I'd be inclined to look a the wiring diagram.

If the clutch does not cycle and the evaporator freezes up, it wont damage it, but the air flow across the evap gets restricted and the cooling is diminished. Shutting the AC off lets the ice melt away.
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☮️

[turbo2cv]

Thank you rsxrs for your response.

Yesterday I discovered that when shorting the two grey wires (number 1 and 2) the compressor obeys nicely the command of the temperature control knob: it keeps running when asking for max cold and shuts off when knob is turned back. So that "compressor shutoff" control board seems to work just fine.

Opened the A/C cabinet in the rear and found the same two grey wires connecting to the evaporator temperature control sensor. The sensor seems faulty: even in 70degree F it does not provide continuity. Jumping the sensor is equivalent to jumping #1 & #2 above.

So I jumped the sensor as a temporary fix. For now I cannot locate the part online. I'm pretty sure I saw it previously at van-cafe, but cannot find anymore. I can see the expansion valve.

With the current performance of my A/C however I doubt the evaporator could ever ice-up, so the temporary fix may last a while. I need to check the pressures. With 70F ambient the air comes out at 50F.

Snurf: you may want to try this fix (jumping wires 1&2) instead of yours. The advantage over your method is that you keep the A/C temperature knob.

[wyldryce]

I'm in a world of hurt on this currently. Just got done partially charging my '85 EJ22 powered with envirosafe...prior owner swore that the AC worked, but I noted that a hose wasn't secured properly and had been abraded/ruined by an axle.

In any case, got it whipped into shape today and couldn't get the compressor to fire. Traced it back to under the dash, and notice that I have the flat white plug hanging in the rats nest of delightful VW oem wiring, but can't spot the temp control relay at all. I think it's missing, unless it's mounted somewhere super obscure.

I perused the classifieds, and found A/C wiring, including that part, but the seller just got back to me and told me the box was taken quite a while back...

I'm about to embark on a coast to coast move, and I've been tasked with driving the camper, while my wife, daughter and dogs get to fly in one day. To say nothing of the heat wave that the country is enduring; It's a deal breaker not to be able to have a/c. Surely a fellow Sambanista can help me out with this "Genelco" temp control box?

HELP!

[wyldryce]

Well, it appears people may not have a lot of answers or spare parts for these older vans laying about. So I did some significant research based on the above part number for the black "Genelco" pictured in the first posts of this thread.

I scoured ebay and found a part that looked close from the crappy picture he had posted. NOS in box. Motorcraft PN YH-396 (which also now appears obsolete)
This one is a slightly different part number.
Genelco
2-25094
364930(5)f
14-992A


In comparing the part that just arrived in the mail to the pics earlier in the thread, it looks like the number 5 pin (brown wire, and therefore likely ground?) has been located to pin "9", which our VW plug doesn't support.
As everything else on the unit looks very similar, with the exception of a resistor and a cap (I'm no electrician), I'm thinking my solution is to resolder that number 9 pin into the number 5 slot, like the original VW. I will then solder in a jumper wire over to the number 9 spot to pick up whatever components that were on that trace? I may initially forgo that part to see if it works so I don't smoke the whole thing.

Anybody see anything glaringly wrong with my plan?
Thanks in advance for any advice!

[Ahwahnee]

I'm no EE either but your plan looks doubtful to me. Compare the solder-side of your board to the one in the prior post.

The boards seems to have similar layouts -- i.e. terminal 9 looks like the same basic circuit, but unused on the VW unit. Terminal 5 is joined with terminal 4 in both examples (but no pin on yours).

If anything it appears to me that you could (as you say) move pin 9 to make it pin 5 - but no jumper wire.

Get more opinions if you can -- I'm just guessing (which is okay if I am a good guesser).

[Ahwahnee]

Perhaps a side by side comparison will make it clearer...

See how moving the pin on yours from 9 to 5 may be enough to get it done without a jumper to anything?

[wyldryce]

Agreed, and thank you. That's what I decided to do at first. Unfortunately, not energizing the clutch wire, with temp control to cold. Now to do some testing at the plug of the relay to trace whether I have a wiring issue.

[wyldryce]

Well, an update:
I had no resistance on the grey wires at all when module plugged in. Went back and made a jumper assy for the temp sensor on the evaporator fins, still wouldn't energize relay.
Yellow wires had appropriate variable resistance based on the temperature dial setting.
Not sure what moving the pin from the number 9 slot to the 5 slot did for me...
The only way to energize the compressor clutch was to jumper the green and red wires. I confirmed that all will operate without the module actually. I'm not sure it is serving me any purpose.

I get no activation of Rad fan when initially turning on A/C, only when temps of the engine demand it, though it is a EJ22 conversion, so that may make a difference.
I'd like things to work "correctly" but I'm not sure what to do next.

I do have the a/c charged up now though, and blowing ICE COLD, so I can live with a jury-rigged system if I must. I am currently leaving the relay module in place with the jumped wire, just it case there is some functionality I am missing and I'll insulate all my jumpers well to make them road worthy. I'm happy to have the A/C for the cross country trip, but wish I could make head or tails of why the module won't energize the clutch, short of me jumpering the power. Clutch comes on/off with the A/C interior fans switch now.

[akstier]

Wyldryce,
I'm in the process of gutting the factory A/C wiring out of my 86 weekender. My van has the relays and Genelco Thermostat Module behind the fuse panel in front, no relays in the back. A PO removed the rest of the system, I am only removing the wires. If you are still in need of a Genelco box, I'd be happy to pass it along to you.

[cobysmolens]

83-early 86 Vanagon AC was a dealer add-on option, possibly only in the US, and is very different from the 86- version that was VW official AC. If you don't have the add-on cover inside the rear closet, you have the early dealer-option system. Dave (DJKeev) did a great job of sleuthing out the wiring and component relationships for this system here on theSamba at https://www.thesamba.com/vw/forum/viewtopic.php?p=7612263.
_________________
Coby Smolens
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