Hello all,
After 50 years of dreaming I finally got my first Corvette Monday. a 1999.
The previous owner shorted two of the wires, red and yellow I think in the small harness that goesto a plug in the low pressure side of the AC. He did this to keep the auxillary fan, closest to the motor, running all the time to keep engine cooler.
With this set up the AC will not work. I re connected these two lines, he had not cut the black wire. Now the AC compressor runs and the fan if off.

I only get hot air from the AC. I checked the high pressure AC line and got 45 PSI. I don't have connector to check low side.

My question is have other people altered the wiring as he did and could he have changed some other wiring that interfers with obtaining cold air. He did this in 2002 so the AC has not been used for several years.

I know just enough to get into trouble so could use some help here figuring out what to do next.

Thanks for any help. Hot in RI.

 

Some people really do a cob job on cars. What an idiot. Screwing up the car and not accomplishing anything. The AC is one of those systems that has to be run all the time to keep it working. If not run the seals go bad. If you are lucky it may just need a recharge.

If you are getting 45 psi on the high side with the compressor running your high side pressure sounds very low. First let the engine cool down and if you can find a way to connect to the low side determine if the low side and high side are the same psi. Should be around 50 psi without the engine running. == See what I mean about low??

If the pressures are below 10 psi you need to add 1 lb of refrigerant and check for leaks and fix any you find.

Here is the SM Diagnostic Procedure:



You should also use the On Board Diagnostics and see if any HVAC codes display on the DIC.

Probably a good idea to see if your fans work on both low and high speed as well. Both fans should run at the same time. On low speed they are hooked in series so each sees half the voltage and on high speed they are hooked in parallel.
Here is the fan schematic:


Bill

 

Thanks for information Bill. I will look it over and see if I can follow suggestions.

I read in this forum somewhere that the low side has the larger fitting and the high pressure has the small fitting. Is this correct? The hose in the recharge kit I have only fits on the smaller fitting! I was under the impression that you should add freon to the low side. So you can see I am a little confused.
Bob

 

Here's a thread that will help you. http://forums.corvetteforum.com/show...ghlight=ac+101