I had a garage repair the heads on my 94 Vette.

They did a really good job & really was happy. My a/c stopped working right before I had them do the repair so I had them re-charge my a/c & to make sure everything was working. At first they said my cooling fans weren't coming on & then called to tell me they were. Honestly, at this point I was getting concerned because some questions I asked about the car, they seemed pretty clueless on. Well, I got the car back & to my knowledge, seemed ok but I didn't drive it for a month. When I went back to driving it, the a/c didn't work. So I brought it back, they ran a dye check & said they couldn't find anything. They think the leak must be in the evaporator because thats the only place they couldn't check.

When I turn my a/c on, I don't hear the clutch fans engage like it used to. Also, the fans don't come on when I turn on the a/c. this always worked & they were trying to tell me it didn't. I'm pretty on top of my car & know when something is working & when it's not. Kind of hard not hearing it when you press a button.

Is there a connection of the a/c not working, a/c clutch not engaing, & engine fans not coming on?

If the a/c is not working, shouldn't the cooling fans operate in the same manner & come on especially when turning on the a/c control button?

At this point, I won't bring it back. They did a good job on the heads, but electrically, I don't think they have a clue and did something I can't figure out. I sure they hell don't want to pay $1200 (since thats the quote they gave me) for just fishing for some answers & replacing a eveaporator which may not be bad. I checked all the connections & didn't find anything loose or a fuse thats burnt out. When the a/c went out before I brought it down, I could still hear the clutch engage & the engine fan coming on.

 

The a/c will only command the fans to come on, if it is working properly. This means the system has to be charged, and the clutch engaged.

Just the fact that you turn on the a/c control button will NOT cause your coolant fans to come on.

 

thanks

now this still baffles me on one thing...

When my a/c went out (originally)...everytime I turned on the a/c...I could hear the clutches engage/disengage & the engine take a rpm change because of the load of the compressor. This all seemed normal except for the fact it was blowing warm air.

Then when they supposedly "charged it"...& still didn't work....I stopped hearing the clutches engage/disengage & the rpm drain on the engine went away.

And now they want to start replacing parts just because they don't see the dye leaking because the part is encased. The quote of $1200 seems 'out there' especially sinced I paid $150 for a diagnosis that they are 100% unsure of.

Any suggestions?

 

"They did a good job on the heads,"

Loose or broken wire to the A/c clutch damaged while replacing heads?

A volt meter on the clutch connector ( when a/c turned on ) should show if you are getting power to engage compressor clutch.
No engage = no pressure change in system = no A/c command fan on.

The fan on with A/c is controlled by a pressure switch ; not a direct connection to the A/c on button.

 

Find a good A/C shop and have them check it out with a sniffer. A leaking evaporator can be confirmed without disassembling anything. And they'll be able to find where any leak really is. I paid $50 for this diagnosis including a partial recharge/evacuate and they credited all of it to the repair bill (even though I did most of the work except for the recharge).
If you have the knowledge, first check out the compressor wiring and voltages as suggested.
Good luck.