Automotive Air Conditioning Information Forum

A friend of mine that’s a truck driver txted me about his ac not blowing cold. Can’t put gauges on it until tomorrow. He said the clutch on the compressor stays engaged, but hasn’t been getting any cooling since yesterday. He just called and said it has started Cooling again. It has Paccar motor and I think a Sanden compressor. Would the expansion block be the first place to look?

Evap may have frozen up. Refrigerant level and cycling would be areas look into.

Check the clutch gap as well. A class 8 truck picks up a lot of miles in a year.

Got to put gauges on it today. It seemed to be working as it should. 30 low and 150 high on high idle. Vent temp 52. It was 78 and humid. Low side had condensation all the way to the compressor. He said he shut the truck off Thursday night and hit the road Friday. Said ac started to work Friday evening. Sure sounds like it froze up. I’ll ask a few more questions Tomorrow.

Friend said the truck sat overnight with the ac off and it didn’t work the next morning when he tried it. Later that day he tried it again and it started working. Weird.

Weird. Almost like the clutch is not engaging?

It was still working as of yesterday.

When we were troubleshooting over the phone, he said the clutch was turning. I’ll post a reply if we ever find out what happened.