How often does your AC compressor cycles?

[klroger]

7milesout, some Chrysler products used a variable displacement compressor instead of a cycling clutch. Maybe that is what you have??? I know the minivans & cars used to have them but I don't know for sure about the trucks. Just thoughts...

[7milesout]

My truck is a 2000 model. And a 3/4 ton. I'm pretty sure it used the lowest technology, old school equipment that was possible to be used in probably every instance across the whole truck ... even for the year 1999. There's no way it is variable anything. It even uses a recirculating ball steering ... not rack and pinion. But this old school equipment is generally tried and true. My truck breaks very little.

[Fummins]

I have been mistaken...I'm relatively sure I've seen the compressor kick in and out on most vehicles that I have looked at? Maybe they were a little low? Probably...

I had a 2017 Mirage with driver complaining of no ac. Compressor was kicking on but zero cold air, blend door and temp controls were working properly. I did the typical try and stuff a can of ac in it and that didn't work. The one single gauge on the low side read around 35psi. Then it went really high with the ac turned off. Just for sharts I bled off some juice(into an epa approved container of course). Pulled it into the shop this morning out of the heat, tried the ac in a can again and now it seems to be working? I haven't stuck a thermometer down the vent yet but that'll be the next step. The ac compressor appears to be running constantly....So that's neat.

I did jerry rig a 2015 fan into this 2017 so the fan now only has one speed. High. I wonder if that's why the ac wasn't working properly???Refrigerant level may have been fine but the fan wouldn't run at low speed and pull enough air through the condenser?

It's supposed to get up to 86F here today. Which is way too hot!

When we were out camping last week it got down to the low 40'sF (single digits in Celcius) at night then high 80's during the day.

[7milesout]

The one single gauge on the low side read around 35psi. Then it went really high with the ac turned off.

When you say it went really high, approximately how high?

[Fummins]

95? Possibly? It's fine

[7milesout]

I was gonna say, that's normal on the low side when the compressor shuts off.

[luckyforrest]

Hi Klroger, I am not 100% sure if the refrigerant level is low or not, the vent airflow temp was about 5-7 while driving on highway, ambient temp was about 29. I just recharged it a bit this afternoon, what makes me confused is the gauge only increased a bit, maybe 3-5 PSI after I used ~70 grams of R134A, and the lowest pressure was ~30 PSI when compressor engage (it was about 29-29 PSI before the recharge). The airflow temp was about 5.5-6 while idling(ambient temp. ~31 ). I also roughly measured the amount of R134A I recharged into the system, it was ~80-90 grams. So for the past 2 weeks, I have in total recharged about 150 grams of R134A! The capacity of the car is only 270 gram. Now I am worried I over charged it. I also used an electronic Freon sniffer and checked the pipes today, and found the vale at the L pressure has a slow leak. It can only be detected after I removed the cap and put the tip of sniffer very close to it. Probably I need to take it to dealer to fix the leak?

[luckyforrest]

I drove the ole Ram out last night just to clean it up and let it stretch its legs. The A/C system was reset last spring to the exact amount of refrigerant for which the system is designed. Yesterday it cooled extremely well. The truck is 23 years old and the AC system has only been touched by me. When I pulled up to where I was going, I let it idle, popped the hood, and the compressor never stopped.

LF - Are you certain you're not considering the radiator fan operation for the AC compressor? Or are you actually watching the clutch on the compressor when you time the on/off intervals. I don't know if the compressor works simultaneously with the AC clutch or not.

I watched the clutch, it cycles, I just recharged (probably over charged!) today and it still cycles ~4-5 seconds pause and 9-10 seconds engage. Air vent temp was 5-6 seems normal so far.

[AtomicPunk]

I also used an electronic Freon sniffer and checked the pipes today, and found the vale at the L pressure has a slow leak. It can only be detected after I removed the cap and put the tip of sniffer very close to it. Probably I need to take it to dealer to fix the leak?

Get a cheap Schroeder valve tool and try and tighten the low side valve first. That's a common place/ reason for a leak detector to go off. Was the cap on when you checked it?

[luckyforrest]

Get a cheap Schroeder valve tool and try and tighten the low side valve first. That's a common place/ reason for a leak detector to go off. Was the cap on when you checked it?

Hi AtomicPunk, the detector did not go off when the cap is on and tight, it only triggers the alarm without the cap and the tip of sensor very close to it. Could that probably caused by my repeatedly connecting to the gauge and damaged the valve?