GM Truck Club Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
I just changed the compressor, accumulator and dryer and recharged the system. Also, just had the air inlet actuator replaced. I noticed the compressor (clutch) never stops spinning, regardless of what fan speed and/or how cold it may be in the cab. Could the culprit be the switch that is located on the accumulator? I've heard it is called the low psi switch, and/or, the clutch cycling switch. Any assistance would be appreciated. TIA James
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #2 ·
Well, replacing the switch located on the accumulator doesn't seem to cycle the compressor clutch. Maybe if i begin from the day i purchased the truck, this might help diagnosing the problem. I bought the truck about 5 weeks ago (early June). During a trip, the vents began blowing warm air and we noticed condensation forming on the blower housing and water beginning to drip on the passenger floor mat; I assumed the evaporator was icing up, and/or, the drain tube (out of fire wall) may be plugged. turning the AC knob on and off the entire trip was necessary to stay somewhat cool. The next day (after a 300 mile trip) took truck to a mechanic and he said the compressor was shot. Went to O'reillys and bought a new (not used) Murray compressor, accumulator and orifice tube. Mechanic installed it and drove it and said it was working satisfactory, but, did tell me the re-circulation door wasn't operating and that it could be in the control head. I told him i would look into it.


We drove home a couple of days later and the truck was cooling much better. However, there was still condensation on the blower housing and puddling on the floormat. I assumed this was because the system was trying to cool incoming 95degree air and not cabin air, or, there was still some pluggage. Fast forward to last week, i had the actuator replaced on the air inlet door. Definitely could tell the difference while driving around in town, and, i never noticed any condensation develop on the blower housing. I figured the problem was fixed.


Last Wednesday, we made the same 300 mile trip to visit my wife's parents. Everything seemed fine, but, close to our destination, i noticed the passenger floor mat was a little wet. I also noticed the condensation again on the blower housing. The next morning, i popped the hood, started truck and turned the AC on, cranked on high. Within a 20 minute span, i realized the clutch never cycled off; it just stayed spinning. Still not knowing exactly what this switch did or was called, i replaced it with one from NAPA. This still did not allow the compressor clutch to cycle.


On the way home this past Saturday, the AC ran fine; however, there was still condensation around the blower housing and some dampness on the floor mat. With what i've just posted, does anyone have any ideas what i should check for next?? I'm short on funds and don't really want to take it to a mechanic unless i absolutely have to. Any help at all would be greatly appreciated. thanks, James
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #4 ·
Ray, last evening, i swapped the relays and this did not solve the problem. I let the truck run at idle for some time, playing with the fan and temperature settings; although the cabin was very cold, the compresser clutch would not disengage; I also noticed there was quite abit of drainage coming form the evaporator drain tube, more than what i think should be the norm. With the truck running and the AC on, i pulled the connection immediately at the clutch and it stopped rotating; i plugged it back in and it began spinning. Also, i noticed the discharge line (from compressor to condenser) was quite hot, to the point i couldn't keep my fingers on it. Not sure if this is normal either. The low side line leaving the accumulator and back to the compressor was cold and sweating, as i would expect it to be.


I took a photo of the compressor with my phone but cannot figure out how to attach; when i do, i will. This is a new compressor i bought from Oreilly's; it is a Murray. Anyone know what my next move should be?? thanks, James

- - - Updated - - -

Auto part Engine Vehicle Car Automotive engine part


Here's the compressor. I have never seen a clutch face such as this. It looks like the three biscuits are are attached and cannot be removed. Also, i failed to mention earlier that the gap (or clearance) between the clutch plate and pully is very minimal; I didn't have my feeler gages but would say it was around 5 mils. Also, just left Oreilly's and had them produce me another Murray compressor. This compressor didn't have the same clutch face, but, the gap was very similar to the one i have. Could this be a clearance issue, keeping the magnets from releasing? thanks
 

Attachments

·
Registered
Joined
·
15 Posts
Discussion Starter · #6 · (Edited)
Ray, i haven't done this yet but will when i make it home this evening and get back with you. I only saw one A/C relay in fuse box under the hood and will pull this one to see what happens. thanks, james

Alright, i pulled the relay and the clutch disengaged; plugged back in, started up again. Not sure where to go from here but to another AC mechanic. Any suggestions? TIA
 
1 - 4 of 4 Posts
Top