electronic touch climate control

[Guest]

Where can I find service information and wiring diagrams and circuit board schmatics for buick's Electeonic Touch Climate Control as used in my 1985 Riviera. The indicator lights blink and often it fails to provide heat / cool as requested.

John 1985 Rivi

[NTX5467]

John --

I'm not sure if there is a web-based location you can get that information from. Perhaps someone from the Reatta Forum might have some answers in that respect.

Otherwise, the Buick Service Manual for that year would be the best place to look--not a Chilton, Clymer, or Motor manual--as some of those systems had different kinks and whinks from year to year. Might be a mode actuator or servo not doing as it's commanded. On the non-electronic systems, when a vacuum supply line from the engine has a problem, the default mode is floor and defroster air output. It's been a while since I looked at those earlier systems, I suspect they are a combination of vacuum and electronic control.

Therefore, you might start by checking the vacuum lines and any junction tees in the a/c vacuum harness under the hood. There was a vacuum check valve with a tee built in for the cruise control vacuum feed that tended to break with age and your vehicle could have one of them.

There is a blower motor control board that usually mounts in the a/c housing under the hood. It will control the blower motor speeds. On the ones for a few years later than yours, they look like a big heat sink with a transistor and a small circuit board build in (after you get it removed from the housing). When it malfunctions, the blower will not work or just work on one speed. It takes the place of the blower motor resistor on the non-automatic a/c system, but the two are not interchangeable.

I don't know if those earlier systems were sensitive to the level of freon charge in the a/c system as the later model units are. If they are, that could be an issue too as the a/c compressor will run during certain heat or deforst modes to help dehumidify the output air somewhat.

Hope this helps,

NTX5467

[JohnO]

I had an 85 Riv. One day the fan would not shut off even with the ignition off. I asked around and was told that the panel

inside the car never goes, but there is a card that sometimes develops problems. Brought it into the shop and they replaced

this card. It is in the eng compartment, passenger side just off the firewall, and held in by I think two bolts. Very easy to replace. I

It did the trick. If I were you I would pull it out and see if anything looks like it got shorted out.

[NTX5467]

That's the blower control module I mentioned. When you get it out, it looks like a big finned aluminum heat sink with one transistor on one side and a circuit board on the other side, typically. Easy to change, as you mentioned.

Thanks for the input,

NTX5467