Finally finished the serpentine swap last night. Started the car to try to charge the A/C and the compressor didnt want to work. The wiring to the compressor is putting out just over 5V (not sure what it should be) and I only got 3.5 ohms across the pins in the compressor itself. The kicker is that ,if I jump the pins in the compressor directly from the battery, the clutch will then engage (did this with engine off, of course). Anybody have any ideas?

 

the ac clutch will not engage if the pressure in the s ystem is dangerously low.

 

What do you recommend for getting the system charged? I'm really wanting to do this myself and not have to take it to someone. I'm not incompetent, just unexperienced with A/C systems.

 

well, if you start charging it, the pressure will build until the clutch engages. As it pumps, the pressure will drop, and it will shut off, only to turn on again after the pressure normallizes. Your AC system is in good condition correct?
Make sure to put plenty of oil in it.

 

I've put as much of one can of 134a that would go in the system without the compressor engaging. How do you recommend getting more in the system? Everything in the system looks to be in good order with new condensor and dryer and I removed and flushed the evaporator. The system has plenty of oil.

Thanks for the quick replies.

 

If I am reading this correct, you opened the AC system, and replaced the accumlator (drier) and condensor and you flushed the evap. If you did all that, the correct way to charge a system is to put a vaccum on the system and add oil, for what you replaced/flushed you should add approx 5 oz of oil, (dont have my book in front of me, but that would be close), once you can hold vaccum at approx 26-28 hg's, and the system holds that vaccum, no leaks, then you can charge your system to facotry specs. There should be a sticker on fan motor telling you how much freon your system holds. I tired to charge my system like you are many years ago and would never get cold, so finally I purchased all the AC tools to do the job. In fact I just did my system (89 Firebird, w/ R-12) The air temp, was 38 deg, nice and cool in my car!!
Hope this helps.

 

in that case, throw a gauge on the system. If you take a look at the accumulator, you will see an electrical connection on the side. This is the pressure switch. Take that off, and jumper the connection. The clutch should engage. Again, don't leave it on too long or your compressor is toast.

 

I dont have a pump that can pull that much vacuum.

I think I'm going to connect a second can and see what happens from there.

Thanks guys.

 

you can add more freon, what I was saying if you opened the system, then your system should hold approx 48 oz or freon, therefore you will need about 4 cans, so if you only put one can in then your are short on freon, the switch on the acculmator is the low pressure switch and I agree with Toehead, to get freon into a underchared system you must jumper that switch, and make sure you have the MAX AC selected the fan is on high.
Good luck

 

Sound good; I'll give'er another go this afternoon.

 

Turned out to be the power steering pressure switch. I jumpered the connector and things started working like they should.

It's still not cooling very well though.