AC Compressor

[GEMcC5150]

I have a AC compressor that will not engage. It not the clutch will lock in it we put direct power to it. have checked all fuses and relay with no luck. Any Ideas

 

[SoHK_alumni]

Most common issue is it's low on refrigerant and the low pressure switch is preventing the clutch from engaging.

After that, either the low pressure switch, the high pressure switch or the relay could have failed.

Probably would see other symptoms but if the PCM picks up a wide open throttle condition, that too will turn off the A/C.

Alway's possible the fuse is blown too.

 

[GEMcC5150]

Thanks for you thoughts. we found it was not getting current from the AC controler. install a hot wire through a switch and it now cold.

 

[DingoNatas]

Mine did the same. I pulled the EATC, opened it and found a bad solder on the internal Omron relay (inside the EATC unit). I re-soldered the four pins of the Omron, problem solved.

 

[bobflood]

+1 on this. Common issue; you can resolder, or replace HVAC head unit with a refurbished one for about $100.

 

[snoopster]

Mine did the same. I pulled the EATC, opened it and found a bad solder on the internal Omron relay (inside the EATC unit). I re-soldered the four pins of the Omron, problem solved.

THANK YOU DINGONATAS!!

I was pulling my hair out.

I had traced my "No Clutch Operation" symptom to no Voltage at the A/C Clutch Cycling Pressure Switch mounted on the passenger side near the firewall. Should have 12V when EATC is calling for A/C. This told me the problem was up-stream but I didn't know where to look next.

Pulled the EATC, opened it up and just like you said, the solder joint on the relay had fatigued, overheated and gone open circuit. I removed the old solder and re-soldered it. Hopefully good for another 20 years!!