LB7: Intermittent ac issue

[JHForman]

So this has happened twice now, similar but different. I have checked all pressures and the system is properly serviced. The other day I was cruising down the rd with the ac on and it turned off, it came back on about 5 mins later and stayed on, it had been running fine for nearly an hour before kicking off. The second time I was driving and turned it on it wouldn't engage, tried for several miles to get it to kick on bit no luck. Turned the truck off then back on and it worked and stayed on for the rest of the trip(3 hours), how do I determine what the issue is? In leaning towards control panel but with it being so intermittent I'm not positive that's the problem.

 

[blk smoke lb7]

Hard telling could be ignition or bcm or .......

 

[Dirtymaxx03]

My AC was doing something similar. Chased it for a very long time until one day I noticed smoke coming from my dashboard. The unit for the AC in the dash itself was going bad and causing the issue. Once replaced my AC has worked flawlessly.

 

[JHForman]

The heat/ac control is what you're talking about right? I believe that is my issue also.

 

[Dirtymaxx03]

yes. the unit with the knobs and temp selection. We looked over what felt like miles of wire, used a million gauges and it turned out to be an easy fairly cheap fix

 

[chevyburnout1]

A quick and easy test to try. When the a/c does stop working open your hood and tap on the a/c pressure switch located on the passenger side by the firewall. See if it kicks the compressor back on. I've seen a few of those low pressure switches fail.

 

[THEFERMANATOR]

Don't forget to check the basics FIRST. When it won't come on go out with a screwdriver or something and push the clutch plate a little and see if it engages. It is rather common for vehicles with over 100K miles to get excess clutch clearance and not engage all the time. Not saying it's your problem, but check it first as it normally isn't hard to reshim the clutch.

 

[Rikter]

I'm in a similar spot. AC runs for 30 minutes after startup, slowly becomes warm after driving for 20 minutes. A look under the hood showed the clutch not engaged. Park & shop for 30 min. AC worked for 5 min then just hot.

 

[zakkb787]

I'm in a similar spot. AC runs for 30 minutes after startup, slowly becomes warm after driving for 20 minutes. A look under the hood showed the clutch not engaged. Park & shop for 30 min. AC worked for 5 min then just hot.

Kinda what just happened to me. Knock off cheap brand compressor. It'd work great then slowly get hot. Now the clutch is gone. 2 months old too.

 

[Nutznky]

Have had the same issue with mine all summer. Replaced the control panel and still does it. Have also replaced the blend door actuator as it was bad when I bought the truck.