A/C problem

[87 national]

Last year when i bought my car the A/C compressor clutch would not kick in. So i had the system drained and recharged. I jumped the low pressure switch and still nothing so today i tried a different relay on it while still jumping the switch, and still nothing no juice to the plug on the compressor at all i checked it with a test light. Also only one pin on the plug for the relay is getting juice with or without the A/C on.

 

[mikestertwo]

Which pin on the relay has power? You should have power on pin "A" all the time with the key on. You should have power on pin "D" when the AC selector switch is in the "AC" position and the pressure cycle switch is made (on).

 

[williamsGN]

http://www.turbobuick.com/forums/search.php?searchid=2528715

If this isn't a viable link, I searched 'compressor' and 'jump' in the general tech section and came up with dozens of threads that may help you.

 

[87 national]

pin A

Pin A must have the juice going to it because it light up with a/c off and a/c on. What would cause pin d not to get juice?

 

[mikestertwo]

What would cause pin d not to get juice?

Blown Heater/AC fuse, bad AC selector switch, or pressure cycle switch not made. Check to see if you have any power on the pressure cycle switch.

 

[49-blues]

Did you put gauges on to check refrigeration pressure-sometimes especially with R-134 which have smaller molhecules you can loose some or all the charge over the winter months cause dried seals will leak the freon.

 

[87 national]

Blown Heater/AC fuse, bad AC selector switch, or pressure cycle switch not made. Check to see if you have any power on the pressure cycle switch.

I will look into this tomorrow, the pressure cycle switch is the one on the side of the dryer?

Did you put gauges on to check refrigeration pressure-sometimes especially with R-134 which have smaller molhecules you can loose some or all the charge over the winter months cause dried seals will leak the freon.

I checked it a month ago and it was good. Also even if it was low it should still kick because i am jumping that switch correct?

 

[87 national]

Today i did alittle more looking into my problem and what i have found is i have power to the pressure cycle switch and also two pins on the relay now, but still no power to the compressor. So i pulled off the plug on the ac hose behind the compressor and when i run a wire from a ground to the farthest left pin on it (looking from the front) the fans kick in, but again no power to the compressor plug. Does the compressor plug ground thought the compressor? Also which way does the plug face on the compressor?

 

[Sal 87WE2]

The three wire connector is the high pressure cutoff switch. 2 of the 3 wires are tied in with the low and the high speed radiator fan. The 2 prong connector on the compressor clutch has relief's so that you cannot install incorrectly, someone will surely correct me if i am wrong.

Hook up some gauges first to verify you do have a charged system and lets go from there...

 

[87 national]

I hooked up my gauges today and it read 10 psi it was charged September of last year. So i must have a slow leak. I want to get my clutch to kick on my compressor first before i refill it, because i do not want to fill it then have to drain the whole system to change a bad compressor. So far i have power going to two pins on the relay and have tried two different relays. There is no juice going to the plug that goes into the compressor i checked with a test light so i am losing power between the relay and the compressor. I also jumped the low pressure switch so it should kick in even with out a full charge of freon. What could possibly be going wrong? It is becoming warm and I do not want to go thought another summer with out air!
Any help is greatly appreciated!

 

[49-blues]

John-I can stop over with everything needed this week-just let me know when is a good time for you.