Ac has static pressure but won't engage
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Rookie
Joined: Jan 2018
Posts: 76
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From: DFW
Ac has static pressure but won't engage
Hi all,
had an issue with the alarm being set on my truck and I didn't have the fob I disconnected the battery, and looks at the fuses but couldn't find a way to reset the security. Then I found a article that said to unlock the drivers door and the security light went away
had an issue with the alarm being set on my truck and I didn't have the fob I disconnected the battery, and looks at the fuses but couldn't find a way to reset the security. Then I found a article that said to unlock the drivers door and the security light went away
Since then my AC stopped working. I have about a 150 psi static but the AC still won't engage. I swapped the AC relay with the fuel pump relay and truck started AC still not working. What else should I look at the resolve this issue?
thank you
thank you
Record Breaker
Joined: Apr 2013
Posts: 1,815
Likes: 56
From: Alberta
pull the a.c compressor relay and check for power. one pin should have battery voltage at all times, one should have battery voltage with the key in run. if that's ok. install the relay.
put your finger on the relay, have someone start the engine and switch the ac on and off...you should hear the relay click and feel the relay engage.
-if the relay engages...check for power at the compressor clutch... check for grd at the clutch black wire.if you have power and grd at the clutch but the clutch is not engaging...the clutch may be no good...ohm check the clutch...there will be a diode in the circuit so you will only get continuity in one direction with an ohm meter.
-with the engine running, briefly jumper the a/c low pressure switch pins together with a jumper wire...verify if the compressor engages. if the compressor works. verify the charge level. the only accurate way to do this is to recover the system with an a.c machine. 150psi static pressure is high enough to keep the switch closed...but it always good info to know what the charge level is. if the charge level is ok...try replacing the low pressure switch.
put your finger on the relay, have someone start the engine and switch the ac on and off...you should hear the relay click and feel the relay engage.
-if the relay engages...check for power at the compressor clutch... check for grd at the clutch black wire.if you have power and grd at the clutch but the clutch is not engaging...the clutch may be no good...ohm check the clutch...there will be a diode in the circuit so you will only get continuity in one direction with an ohm meter.
-with the engine running, briefly jumper the a/c low pressure switch pins together with a jumper wire...verify if the compressor engages. if the compressor works. verify the charge level. the only accurate way to do this is to recover the system with an a.c machine. 150psi static pressure is high enough to keep the switch closed...but it always good info to know what the charge level is. if the charge level is ok...try replacing the low pressure switch.
