Im not getting any power to my ac compressor !What could it be any idea ?Is there somewhere a fuse ?
thanks for any help!

 

What year is your Vette. You may have low referigerant charge, there is a pressure switch in the system to protect the compressor. On my 75 the pressure switch is in the hi side line on the right side of the engine compartment about mid-way just below the edge. Turn it on and see if you are getting power to the pressure switch.

 

What year car? Early and late C3 has a completely different electrical path to the compressor.

 

Its a 1976 !

 

Yes i turned it on and the pressure switch is getting power.Is it maybe the pressure switch because there is no power on the plug from the compressor

 

Do you have any gauges to see if there is any charge? No charge, no pressure, no power.

Also 76E (long compressor) or 76L (short compressor)? Doesn't really make any difference, just curious.

 

Yes i do have a gauge on the bottle to fill the ac and its full
im wondering if that pressure swicht could be bad

 

Ok i found out that the compressor is fine after i cross bridged the cut of switch it started turning and the lines are filled with that new gas but its still ot working .I read that i have to get a vir and switch it out with that old one for the newer gas is that right can i just buy a cheap one on ebay?
thanks

 

There is a 25 amp fuse. Mine is top right on 78. I had the same problem. The ac was lone on freon. Still does not blow cold and going to mechanic Saturday. Went to a GM dealer last year same problem. They charged it and said nothing was wrong. Blew warm went back. They said kjeep using it it will get cooler. Never did.

 

They LIE! It either works on demand, or it doesn't work.

To the original poster, get a set of gauges put on the system... NO problem can be diagnosed without a low and hi side pressure gauge test.

 

Did you test the amount of pressure with the compressor running? If you put a guage on it, it will read high when the compressor is off, and draw down when the compressor cycles on. It should read around 40 psi when the compressor is running.

 

Is there a way that the compressor leaks ?It looks like there is not enought pressure in the unit but as soon as i crossbridge the pressure switch the compressor starts engaging.When i stat filling the unit whil the compressor is not running it shows full of freon as sonn it runs the compressor and i try to fill it it goes from full to empty everytime i hit the freon can trigger.Its not building pressure.I bought the adapterkit for the neuer gas .Is that maybe my problem?
Thanks for all the help i can get

 

Did you remove the old shrader valves before installing the new adapters?

 

you dont have to remove them you just screw them on top thats it .That how i understood the manual
regards
Koray

 

I converted an 80' vette from R12 to R134 over the weekend. I flushed out the evaporator, condensor and a lot of old oil using the flush can from Advance Auto and my air compressor blow gun. installed new Accumulator, new low pressure switch, and 6oz PAG150 oil. I put 2 oz in back of compressor and spun clutch by hand to cycle oil in. Added 2 oz to evaporator line, and 2 oz to condensor line.

Got R12 to 134 conversion kit from Advance. They simply screw on over the old schrader valves. However, we could not get the car to take freon. It turned out, there was a little black rubber piece inside the new low pressure connector, which was preventing the freon from going in. Not sure what it was for, but I removed it and reinstalled new valve, re-vacuumed for 30 minutes. Hooked up gauges and I could hear the first can of freon get drawn into the lines within just a few seconds. Had to bypass low pressure switch with a jumper wire so compressor would stay engaged.

My guages showed 45 low/ 260 High after adding 48 oz of R134 (R12 would be 60 oz, so it should take 10% roughly of R134). Air is blowing out the vents at 50 degrees and outside air 95F. Also added dye so I could find leaks in the future, but my fingers are crossed that all the new O-rings will keep that from happening.

 

thanks will try the same !!!!

 

If you use any of the 90 deg adapters you definitely need to remove the original shraders. I guess I have used a different brand of adapters than you.

 

Its funny i just tried to check the ac out again and i hooked up the bottle with the gauge on it and it showed full as soon i started the car and the ac i heard the pressure switch kicking in the the clutch engaged and after 20 seconds it clicks and the clutcvh stopps again and the gauge on the bottle climbs slowly up to full the pressure switch clicks and the pressure falls down to almost 0 and then it climbs up again the it mskes click clutch engages and it drops again .What is that is there anything in the compressor whats maybe leakingafter it kicks in .

 

no these are straight adapters!
regards
Koray

 

the clutch is cycling as it should, per the pressure. how much freon have you added?

It sounds like its still low on freon. You really need a set of service gauges to truly evaluate the system.

Neal