1985 Corvette

A buddy of mine's zr-1 has a problem with the climate control where it is in constant operation. He said he pulled the part that was causing the problem but that GM no longer supplies that particular part. I'm trying to help him out as he isn't too internet savy and still has 54K dialup on one of those old computers and he doesn't know his way around the internet too well.

I should see him sometime Sunday to check out the part but figured maybe somebody knew what in the climate control system would cause the constant a/c if it malfunctioned? If I get an idea I can give him a price on the part that I could find from on here or somewhere else so he can expect how much to spend on it.

Will try to get pictures tomorrow.


This won't be the last time I post here, his car is running in reduced power mode because of another electrical gremlin that I hope to track down. Sooner his car is running right, the sooner I get to test drive it.

HammerZR1

Welcome aboard. Between here and the ZR1Registry http://www.zr1netregistry.com/forum/index.php?, you will get all the help you need. I'm not a tuner so I am sure others will respond to your requests soon. Search the archives here and over there and see if you come up with anything regarding your problem. As far as the low power, I'll leave that to others to help with when you get ready.

1985 Corvette

Yeah, I told him about the zr1netregistry over the phone and he paused for a moment when I asked him if he had it written down correctly then he said he would just wait for me to help him out. I'll probably be doing a bit of researching and inquiring for him over the next few months to get his car working again, which is fine by me, I get to learn more about the Z.

He's a nice guy that bought the thing brand new back in 91' and it's just now giving him problems and I hate to see it sitting there.

cvette

Can you tell us what the part was or post a picture? Is it the head unit for the electronic climate control? Is it the A/C programmer?

Charlie

corvette1989bham

I am in Birmingham, I also have a 95 ZR1, tell you buddy to contact me at corvette95@charter.net and if he wants to bring it to Bham, I will fix it (or SHOW HIM HOW TO) for free - he pays for parts only - prob wont need any.
Chris

1985 Corvette

Cvette, I haven't caught up with him yet.

Bham: I will give your address to him first chance I get. Thanks for offering to help him out. You'll know more about the car than I would helping him.

1985 Corvette

Okay, just got back from looking at the car some more and the guy pulled the electronic air blower control because he suspected that was the problem. it sits on top of the a/c housing on the passenger side in the engine bay, is a two plug unit and has a pretty good sized heat sink unit attached to it.

According to the electronic diagram, you're not supposed to test the module because it's in a solid state (or some term that I can't remember) and any voltage applied outside of the car could harm the unit. Well, it was done anyway and the conclusion was the module was okay.

A trouble shooting diagram said start first at the A/C Heater control head unit which is right there in the center console. He skipped ahead to the module because he's not sure about opening up the dash to remove the head unit. I'm not and I'm ready to do this but I need to read up on the 90 and up console structure. It doesn't look as straight forward as the 84-89 dash.

Also:

The engine has been running rough because of a bad coil so he tells me and he plans to replace all of them. He was curious as to the price of a few things.

4 H.V. coils

LT5 sparkplug wire set

Enging gasket set

We get all that taken care of and she'll be back on the road.

jonszr1

coils are about 150 wires i used msd 85 plenum gaskets 65 you can pull the plenum without taking off the throttle body those 2 gaskets 75 total .

lite blue

I like my MSD wires, but they were WAY too long. I took mine apart and shortened them up to match the stockers.
I had some weird stuff happen with my '91 A/C controls. I had read up on how to pull codes from the unit, but in the mean time, I unhooked the battery for something else, and it reset and seems to be working fine, now.

Goldcylon

Coils AC Delco $140.00 per set free shipping all day on EBAY

DELCO Replacement wires about $40-$50 also on Ebay

Upper Plenium gaskets about $75.00 not including the TB different shops

cvette

Is the problem that the air blows only one temp?

1985 Corvette

It blows nonstop on high I believe. Even after he has shut the car off and taken the key out of the ignition, the blower continues to run.


If it comes to having to remove the a/c control head unit, can someone link me to console/dash removal of a the 90 model and up cars?

lite blue

That could be just a relay. I had that happen to my Impala.

phrogs

one of the bigest things on these for ac is the head unit in the dash and the programer behind the dash, thats a fun one ill tell you that!

theres nothing special about pulling the head unit just do it, pull the shifter bezel then start on the bezel with the key it has 3 screws that hold it in and a few metal spring like retainers that hold it in. be sure to unplug the power key and then it will move out of the way, The head unit just has 2 screws maybe 3 and it pulls out from the dash.

I have a spare head unit if he needs it taken out of a 91 for $ 100 plus shipping

WVZR-1

If it blows "constant" even when shutoff and key removed it is likely the part that your friend removed. I had that situation and it was the cure. A good bit of diagnostics but it came right down to that. No guarantee but it's a good place to start. How did he arrive at that conclusion? Obviously someone needed to head him in that direction. I was very skeptical of the fix but it's an easy reach.

1985 Corvette

Well, he seems to know his stuff on following the trouble shooting tree diagrams and the service manual and he actually makes a hobby out of rebuilding and fixing arcade machines so I assume he knows a thing or two about tracing wires and finding faulty wires/switches/resistors/etc.

He checked it with one of his instruments and it checked out fine. I'll double check on that. I'll be sure to relay what you said about it to him too. Should see him sometime tomorrow.

Also, is there anywhere else (supporting vendors maybe?) besides ebay where he might find the previous listed replacement parts?

ljobrian

My a/c blower recently started blowing constantly with key off and out of ignition. Following the steps in the tech manual for troubleshooting, it says for this problem to first start by checking the a/c underhood fuse. The problem is that I can't find it. There is a diagram in the manual but the fuse isn't there in the car. Any thoughts as to where it could be?