I've had my 1993 coupe, 6 spd. for a little over a week now. When I got it the climate control wasn't working. I've been researching a lot here and in other places on the web for information. I'm handicapped because I haven't received the manuals yet, they're supposed to arrive this Saturday. I'm going to document what I do to add to the store of knowledge about dealing with this system.

Here's what I've got so far.

• When I got it the compressor clutch wouldn't engage - period.
• The blower fan worked on auto and I had manual speed control.
• The controller buttons were blinking denoting problems and reactions to pushing the buttons was unpredictable.
• I had low refrigerant denoted by code 09 in the control module and a gauge connected to the system confirmed that.

I've got a neighbor that is a mechanic and he has the gauges and refrigerant, 134a, so we did a static charge a few minutes ago but the compressor clutch still didn't engage. We tracked down the clutch relay, pulled it and jumped the proper terminals to manually power the clutch and it engaged and both radiator fans powered up as well. He then filled the system to capacity and I found that I was getting good cooling in the car, all the buttons were on solid and all the system doors were working, I was able to direct airflow to any vent. We then put the relay back in and the clutch shut down and didn't come back on.

Since we were working in the dark we called it quits. Tomorrow I'll disconnect the battery, wait 5 minutes, reconnect it and see what happens. Not sure if disconnecting the battery will clear the 09 code in the A/C controller modules or if I'll have to do that separately.

It appears that whatever tells the system to actuate the compressor clutch relay ISN'T. If I get lucky disconnecting the battery will reset everything and I'll be good to go but I'm not holding my breath.

If anyone wants to comment feel free, I'm flying blind here with no manuals, looking forward to getting my hands on them.

 

I just got back from a 1000 mile run across PA and back in the 'vette. Adding refrigerant to the A/C system fixed it. Everything works as it's supposed to, all doors, control unit buttons, etc., and it blows cold! I dodged the bullet on this one.

Of course I discovered other things that I need to fix; I either have a fuel delivery or ignition problem that becomes apparent under certain conditions, some of the functions on the Bose radio aren't working, ex. scan and search (added to the CD which doesn't work), the rear hatch release button in the console doesn't work, under heavy braking I get a pulsation, I have a balance issue at about 77 to 80 mph (likely due to the damaged right front rim).

 

Actually, both could be symptoms of a warped rotor. I had the same that I could tell was coming from the front left. Turned all 4 rotors and threw on new pads and still had the issue - both a pulse and a vibration.
Bought new rotors for front and they went away!

Congrats on the A/C fix!

 

Cold air is a requirement for a C4... that green house we have in our coupes can get really hot especially when it is 95* outdoors and the sun is beaming down on the Corvette.

I bought a nice set of four slotted/drilled rotors for my C4 at Rockauto and they were less than $400 for the set. I just installed slotted/drilled Rotors on my daughters 2011 Camaro and what a difference it makes with a good set of ceramic pads.

If you have any questions about the C68 get in touch with BATEE.COM as he helped me by fixing my C68 when it was acting all wonky. He can fix it for you or he will sell you the parts to fix it yourself, either way it is fast and affordable.

Best Regards,
Chris

 

I've got a portable garage in boxes sitting in the driveway I need to set up and then I need to figure out how I'm going to get the car up on the air. Once I get it high enough I'm going to camp out under it and start playing with it, doing the things you mentioned starting with replacing the fuel filter. I'm going to be nervous the first time I jack it up and put all four corners on jack stands.

 

Once I get it in the air I'll figure out what's going on with the brakes.

I found Batee.com and was thinking about whether it was better to try to fix the control module myself or sent it to him. Certainly much easier to send it to someone who knows it 'cold'.

 

make sure you search or ask advice on setting it up to jack and use jack stands

 

So was I. I've only had mine a few months.
This video really helped me.

 

Thanks guys, I've watched a number of videos including the one linked. Doesn't mean I won't be nervous the first time I jack it up. I've been around cars enough to realize that one mistake can cause a lot of damage.

The discussion I find interesting is the one about whether or not to take off the top, open the doors, pop the hatch and open the hood before jacking.

 

No, not necessary, don't do it and WTF?

These cars are seriously solid. You can raise the entire side of the car if you put the jack in the middle.

Pinch welds are your friend.

 

Thanks Bill. My '03 Mala-blue is about the same, you have to jack on the pinch welds. I'm keeping my eyes open for a picture or diagram of the corvette's 'unibody' structure to get a better feel for how rigid it is.

Edited to add:
Hmmm, guess I'm still learning about this forum, I didn't think I hit multi quote but there it is. Of course I'm old, maybe I'm just confused?

 

I found an old file with jacking info from the ZR-1 registry- looks like it got was re-done in 2012.
This had an original date of 2004: How to jack up a ZR-1

 

Thanks, bookmarked that page.