A/C compressor constantly cycling

[Rocket Man]

I just did an Efan conversion on my '02 Denali and now I notice my compressor cycles on and off constantly, with the a/c either on or off. I think it might have been doing it before but I didn't notice it; now a fan turns on and off with the compressor so it's real noticeable. I replaced the clutch cycle switch but no difference. If I jumper the switch harness the compressor turns on and off with the hvac control panel. I had the refrigerant charged up a few months ago because it wasn't working at all when I bought the truck. It seems it was working better back then. Could it just be that I need another recharge or have a leak and the low pressure is shutting it off? The shop that charged it seemed to have a problem when they did it.

 

[YukonXL04]

I would check that first. Also it will cycle if you have the recirculation button pressed.

 

[Rocket Man]

I heard about that so I made sure to not have it on recirculate. I hear the compressor also turns on to remove condensation occasionally no matter if the a/c is turned on, so maybe it's trying to remove condensation but it senses low refrigerant so it turns off to protect itself?

 

[01ssreda4]

Low on freon. Classic symptom.

 

[Rivieraracing]

Does it cycle on and off when you have the fan speed to off?

---------- Post added at 03:55 AM ---------- Previous post was at 03:47 AM ----------

Sent you a message, let me know if I can help you out since I've done the same setup with the same harness on my denali!

 

[afpj]

Low on freon. Classic symptom.

Hmm, haven't paid attention until reading this thread. It's been over 100 degrees since June so my ac seems to cycle on off frequently but it blows cold. Is that still considered a sign of low freon?

 

[clandr1]

Did this only start after you did your efan conversion? If so, I doubt it has anything to do with the level of refrigerant.

 

[Rocket Man]

Does it cycle on and off when you have the fan speed to off?

No; if the fan speed is set to off the then the radiator fan stays off.
---------- Post added at 03:55 AM ---------- Previous post was at 03:47 AM ----------

Sent you a message, let me know if I can help you out since I've done the same setup with the same harness on my denali!

It works exactly like you described in the PM so it looks like it's hooked up right.

Did this only start after you did your efan conversion? If so, I doubt it has anything to do with the level of refrigerant.

Like I said in my original post, it may have been doing it before but I probably wouldn't have noticed it. Now that the efan turns on when the A/C compressor kicks in, it's noticeable since the efan makes quite a bit of noise. The A/C still works OK just not super cold. Seems like it was colder right after I got it charged.

 

[01ssreda4]

Hmm, haven't paid attention until reading this thread. It's been over 100 degrees since June so my ac seems to cycle on off frequently but it blows cold. Is that still considered a sign of low freon?

Absolutely.

 

[SLCHOE]

I just did an Efan conversion on my '02 Denali and now I notice my compressor cycles on and off constantly, with the a/c either on or off. I think it might have been doing it before but I didn't notice it; now a fan turns on and off with the compressor so it's real noticeable. I replaced the clutch cycle switch but no difference. If I jumper the switch harness the compressor turns on and off with the hvac control panel. I had the refrigerant charged up a few months ago because it wasn't working at all when I bought the truck. It seems it was working better back then. Could it just be that I need another recharge or have a leak and the low pressure is shutting it off? The shop that charged it seemed to have a problem when they did it.

Low on freon. Classic symptom.

Absolutely.

If the compressor is cycling with the control head in the "A/C off" position, you have other issues, not just low freon level.