A/C Compressor - How to Jumper?

**pajeff02** · 07-01-2014, 02:29 PM

I am working on the AC system in our '07 Suburban. Last night I was able to locate a leaking line to the rear AC unit after partially charging the system with refrigerant. While recharging, I attempted to jumper the low pressure switch on the drier and I still could not make the compressor engage. When I push the AC button on the HVAC panel, the light blinks a couple of times and then goes out. Is there something else I need to do to engage the compressor? The service manual is about useless on the recharging procedure.

**pajeff02** · 07-03-2014, 05:36 PM

I received the rear block off kit this morning and will be attempting to get the system up and running tomorrow.

**2002ssslp** · 07-04-2014, 02:45 PM

What a shame that an 07 vehicle is having A/C trouble already. I hope the new systems are better engineered. BTW. I have a 1998 Jeep Cherokee with 262k and the A/C still works. I guess I'm one of the lucky ones.

**2002ssslp** · 07-04-2014, 02:50 PM

Jeff, these systems are still the old design and I do not believe the BCM has anything to do with the operation so that being said, did you check for 12v at the fuse, relay and clutch ?

**pajeff02** · 07-04-2014, 04:13 PM

I'm not sure what the issue was. I installed the rear block off kit this morning, and then sucked it down to 26 inches of vacuum. It held that for an hour, so then I let the vacuum pump run for a good 35-40 minutes before charging it. Part way through the first can the compressor started working and with the second can going in I jumpered the low pressure switch and the compressor ran like it should. No clue why I couldn't make it spin the other day.

**pajeff02** · 03-07-2015, 04:01 PM

Reviving this thread from last year -

Well, I have hope that the winter freeze will be departing and that the weather will eventually get warm again. As I prefer being cold rather than hot, working AC is a must in our daily drivers. After blocking off the rear A/C lines last year and recharging the system, I once again had cold air in our Suburban. The only issue is that I am now getting a "sucking" sound that seems to emanate from the passenger footwell whenever I run the A/C. The sound is regular and happens around every 30 seconds or so, lasting only about 2-3 seconds each time. It does this no matter what the setting on the HVAC panel, so long as the A/C is activated, and does not seem related to compressor engagement. Any clue?

**0rion** · 03-07-2015, 05:31 PM

not sure if this really helps you much and I'm not real experienced with a/c stuff other than a basic charge but this link has some good info. Is it a gurgling sound? I've had that sound from a clogged condensation drain line which is in the same area you're hearing it. May want to fish a coat hanger up that line and see if it's clogged.

a/c link

Air Conditioner A/C Compressor Failure