LB7: A/C clutch won't engage...

[WanaDmaxsub]

...when I push the A/C button or turn on the defrost.
I can command it on with EFIlive.
Most times if I shut the truck off with the A/C button in the on position the clutch will engage when I start the engine.
No codes.
A/C button light comes on but doesn't flash.
Manual HVAC controls.

Anyone else had a similar issue and found a resolution???

 

[Awenta]

Have you check the pressure? Also try jumping the low pressure switch. I had a loose clutch relay that would give me intermittent problems.

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[THEFERMANATOR]

Is this a new problem that just happened? Was there any tune changes or ecm swap? If you can command it on with the engine running via efilive, then that rules out a pressure switch. The common cause of this is a tune change to a different climate control option.

 

[NC-smokinlmm]

Is this a new problem that just happened? Was there any tune changes or ecm swap? If you can command it on with the engine running via efilive, then that rules out a pressure switch. The common cause of this is a tune change to a different climate control option.

This^^^

 

[WanaDmaxsub]

I had a TON of work done at multiple dealers (Stranded on the freeway with the wife, granddaughter and TT) recently. The last time to replace the fuel filter housing. After that is when I noticed that the A/C wasn't working. That dealer shouldn't have touched the computer.
This issue has been ongoing for a couple of months...most of the time I can get it to work properly by searching for the modules in EFILive (It's almost like something wakes-up and says "ok turn A/C on ..."). But now that doesn't even work.

 

[WanaDmaxsub]

Hooked up the laptop...did a module search with EFILive...got called back into the house to "do something more important than goofing off with the laptop in the truck..." couple of hours later I got back in the truck to make a homedepot run, pushed the A/C button and the clutch engaged...