Climate Control Problems, 1993 Custom

[OldsBuickGuy82]

When I start the car the climate control will not function at all, you can press the buttons a million times but the setting will not change from OFF (the light in the OFF button stays lit) and there is no noice from the fan.

Give it about 20 minutes and it will just magically start to work on whatever setting you pushed last. I originally thought maybe it was the fan, but when it starts up its fine. I can't think why the fan not working would prevent from changing settings from OFF.

Any advice?

[imidazol97]

There must be a connection not making good contact. Is the air conditioning compressor working even though there's no blower or anything?

A really wild idea is there are grounds at the left side beside the parking brake pedal in the vertical part of the car in front of the door. Hit in there to give vibration. If you can find a bundle of wires move them and try to affect the connection. YOu can do the same with the terminals under the carpet and a thin plastic panel between the driver's seat and the door sill--right where the driver's arm would hang loose. Same for the passenger side.

I had a 93 and it developed a quirk where the power door locks quit and the control for the air conditioner did nothing--it reverted to air conditioning with compressor running and defrost for the vacuum mode setting. It did not go to "off" like yours. But it's worth a shot.

[OldsBuickGuy82]

Originally Posted by imidazol97

Is the air conditioning compressor working even though there's no blower or anything?

No, absolutly nothing works, everything is just OFF until such a time usually 10-15 minutes when it all booms in. Once that happens everything is like new.

[imidazol97]

Originally Posted by OldsBuickGuy82

No, absolutly nothing works, everything is just OFF until such a time usually 10-15 minutes when it all booms in. Once that happens everything is like new.

I spent a little time with my 93 manual playing electrical engineer. You have a fuse under the dash going to the control switches. You have a ground in the left side. The first check in the manual that applies to your symptom is to take the dash fronts off to get to the connectors at the control panel. There is a C2 connector with 10 slots, 5 top, 5 bottom. You check there for powerto the switches. It also checks for ground. You can check the fuse under instrument panel. You can try to find the ground connection.

Otherwise it's take the thing apart to check there when it's not doing it. Bettcha if you take it apart and get to those connectors, the thing will work like a charm. Just like when you take a car to the service shop for something, it starts working okay till you're on the way home and $50 poorer.

I can give you the 3 things to check there if you decide to take the lower pieces off the dash to get to it. I don't think you can reach the connector from underneath and be able to work with it.

[grcore]

Is this the automatic climate control (digital readout) or manual control (8 buttons and the fan switch)?

[OldsBuickGuy82]

Originally Posted by imidazol97

I can give you the 3 things to check there if you decide to take the lower pieces off the dash to get to it. I don't think you can reach the connector from underneath and be able to work with it.

I plan to check all those things this week, so please post whatever you think is important.

Originally Posted by grcore

Is this the automatic climate control (digital readout) or manual control (8 buttons and the fan switch)?

It's the manual version.

[grcore]

Then I would say its the control panel, if it was a loose connector it would likely be intermittent as you drive, hit a bump, off it goes. On the "manual" systems, the control panel is the "brains" of the outfit, as opposed to the digital climate controled units, where it is the hvac programmer.

[OldsBuickGuy82]

So what do you recommend?

[imidazol97]

When you get in to the control assembly
there are three connectors one of them is a 10 pin connector
Should be marked A through K.

K J H G F
A B C D E

Pin F to ground is battery voltage through IP fuse block fuse 11
Pin C is battery voltage measured to ground
Pin H to C should be battery voltage between the two

This is the car end of the connector: not the part to the ac control
The key is in run position.

To get to the unit
the lower trim parts pry out gently. The glove box comes out with a bunch of screws. There are then 4 screws inside the louvers for the air condition at the top. The vents gently pull out forward. The screws at the top DO NOT DROP. You will spend a lifetime getting them back out of the heater unit if ever.

This is from a 93 factory service manual

[Salestax]

REPLACE THE CONTROL HEAD!

This is a common problem with control heads both manual and automatic on H body vehicles. There arent any real 'user servicable' parts inside there, just resistors, capacitors, and a silicone chip that holds the logic for the 'programmer' (this controls your vents). You'll often find that your cooling fan(s) may run while this is inoperative as well.
New, they can be pricey. Last one I bought was used for about $65.00

[OldsBuickGuy82]

So, just replace the whole unit will do the job, is that what you mean by control head?...

I've been on eBay looking around and the most available is digital units, can I pop in a digital unit even though it was a manual one originally?

I have my eye on this one;

http://cgi.ebay.com/ebaymotors/91-92...QQcmdZViewItem

[Salestax]

The digital version is the 'automatic' setup, and I dont think its compatible with the manual version. The 'thing' with the buttons, the rear demest, blower speed, and temp slide is the 'control head' I talk about. Just got done removing mine for the 2nd time.

[OldsBuickGuy82]

Ok, thanks to all who replied, I'll check out mine fully and see what I can do with it.

Cheers

[imidazol97]

Originally Posted by OldsBuickGuy82

Ok, thanks to all who replied, I'll check out mine fully and see what I can do with it.

Cheers

I doubt that the units, manual and automatic, are plug compatible. You have the C67 unit and the automatic is CJ2.

The algorithm I listed above is from the manual. The next step is replace the control unit in the dash. I would suspect connection problems. Be sure to remove and replace each fuse involved to insure good contact. I suspect connection (including grounds) because many people with H bodies have had that problem with grounds. I had it, but sold the car without diagnosing it.

The fact that your unit comes on after a length of time suggests something heats up somewhere from engine heat or light bulb heat or something and expands and makes connection again.

As I said earlier I would suspect messing with all the connections when the dig in to get the unit and putting it back may fix it for a while.

Give us a full report.