[Nitrousbutton]

My wife has a 88 Caddy that the climate control goes crazy when you use the headlight high and low beam switch. It will change the settings from turning on the defroster to heat, fan speed from high to low and turn on the rear window defroster when you use the headlight dimmer switch. Also every now and then it pops and the buttons get real warm. Anyone have any ideas? Thanks,,,Perry.

 

[docvette]

Doc here, imp:

Is this all mounted on a single stalk stick for the turnsignals?

Do the headlights get dim then bright with RPM and activation of anything on the stalk stick?

Doc imp:

 

[Nitrousbutton]

Doc, Yes the dimmer switch is on the turn signal. And no the lights don't get brighter or dimmer with rpm change or the use of anything else, It's been doing this now for about 2 years. Also she says if you use the dimmer switch when the climate control is turned off it will turn it on. It's got me baffled. ain: Perry

 

[Y2K]

Can't help ya,just wanted to say I feel your pain.
My old '84 eldo's climate control seems to have a mind of it's own but nothing related to the headlights.
These cars have enough wires in them to reach to the moon and back,good luck.

 

[docvette]

Doc here, imp:

Here is the schematic for your 88 Cad..

Schematic

Pull the codes and see if you have any error codes.

The Climate Control Programmable module may be bad..

Also follow the schematic and check the fuse links on ALL the lighting and CC Systems be sure none are open. It may be robbing power from the other systems taxing them when one has an open link.

You may also have a short in the signal stalk wiring as it passes through the column..and shorting out..you can ohm that out. (move the wheel as you do in case something is rubbing)

Not a Caddy guy at all..but those steps look logical to me.

Doc imp:

 

[T-bucket23]

As silly as it sounds, you may want to check all your fuses. I had an 88 long ago and they are noted for back feeds like all GM's. You may have a problem in the flash to pass circuit that is backfeeding due to a blown fuse. Try it with the lights and sentenal for the lights off and see if it still does it. You can also with a little work just activate the high beam switch at the bottom of the steering column to eliminate the activator rod shorting against something in the column when switching

 

[Nitrousbutton]

Thanks Doc, I'll give it all a try. Thanks again,,,Perry

 

[Nitrousbutton]

Thanks T-Bucket, I'll check that out also. Yeah I know about checking the switch, I replaced it a few months back,,,lots of fun . Thanks again, Perry.