evilbeef54

iTrader: (2)

well a few weeks ago the a/c stopped blowing cold so i went over to checker and bought one of those a/c recharge kits, used the pressure gauge on the low pressure port and it showed very low, barely registering, so i filled it up to the blue section on the gauge and my ac worked perfect, for a few weeks. Now it started blowing hot again, which really sucks because it has gotten pretty warm here. I go to check the pressure with the engine running and now the pressure gauge is reading 150 psi, and the compressor isn't coming on, i tried using a screw driver on the low pressure port and bleeding off all the pressure back down to 0 then figured i'd try to bring it back up to the blue section, well as soon as i hit the button on the recharge can the pressue goes straight to the red section at about 100psi, the compressor just wont turn on. Any thoughts, i really dont want to have to take this to a shop to get raped.

evilbeef54

iTrader: (2)

hmmm okay here's a little more diag. I found a thread on camaroz28 that talks about this same issue (hasn't had a fix yet though) If i try to jump the wires red-grey on the pressure switch the fan comes on but not the compressor, but when i jump pin 85(12v) to pin 87 (to compressor) on the ac compressor relay, the compressor comes on, pressure drops down to the blue and cold air comes out. So why is the compressor not coming on normally? as soon as i pull the jump wire the compressor cuts out and the gauge on the LP port goes back up to 150

samson_420

iTrader: (1)

Sounds like the high/low pressure sensor is not letting it come on.

I do not know the pressures right off hand, I just don't remember what they should be.

samson_420

iTrader: (1)

Just got em'.

Your low side should be running @40-49 Psi in our climate. And the high side should be @ 210-290.

When the car is off the low side will shoot upto about a 100 or so I believe.

evilbeef54

iTrader: (2)

Yeah, it definatly seems like an electrical issue since the compressor comes on when i jump the relay and force power to the compressor, what confuses me is if it was the pressure sensor then shouldnt it have come on when i jumped the wires of the sensor? and yeah when the car is off the lp side does go to about 100 and when the compressor runs the lp drops to the correct range, its just that the compressor doesnt turn on until i jump it

bjamick

iTrader: (31)

Check your connector. Mine sort of did the same thing and after I pulled the motor I seen the electrical connector was dry rotted. Yours may have done this same thing, un-plug it and check it out.

samson_420

iTrader: (1)

Check out the pressure sensor like stated above along with the connector.

Hopefully it is that.

evilbeef54

iTrader: (2)

wires on the connector look good, any technical way to test it with a multi meter? jumping the wires on the lp sensor just turns the rad fan on not the compressor

samson_420

iTrader: (1)

I don't know man. . . . . . . . . It should kick on, as far as I know.

I really can not think of where else to check the circuit.

It sounds like voltage is not getting sent to the relay that turns the compressor clutch on.

evilbeef54

iTrader: (2)

Okay thanks everyone, problem fixed, basically when i re-charged the ac system the one can i used was not enough, after putting in just the one can the gauge read in the "filled" range, at idle. However when the rpms raised the pressure dropped down barely to the "low" range which tripped the lp sensor like we all thought. The thing that was throwing it all off was that the PCM needs to be reset to bring the compressor back online. So after resetting the pcm and watching the needle while having someone run up the rpms we added another lb and now it is all good... for now