TCCoA Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 ·
I know that the compressor should cut out with WOT, but mine cuts out when accelerating lightly. What is the sensor for this? Does it depend on vacuum or the throttle position? Lately it's been in the 90's here in Phoenix.... HELP!
 

·
Newbie
Joined
·
5,650 Posts
The cycling of the A/C system depends only on internal system pressure. There's a pressure switch called the A/C clutch cycling switch that's located on the A/C accumulator. If you don't know, this is the tank behind the passenger shock tower. If your system is cycling frequently, you're probably low on refrigerant.
 

·
Registered
Joined
·
1,272 Posts
You can check it in the driveway. Turn the A/C on max, advance your throttle from under the hood and listen for it cutting on/off. Of course you can use a pressure guage if you have one. Somewhere around 25 is the low pressure cut out.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #4 ·
Turns out that it was low on freon, getting over a 50 degree drop from outside air temp. We hit nearly 100 degrees in Phoenix today ... sure was nice having cold air again. But I'm still curious, what controls the a/c compressor cut off during WOT?
 

·
Newbie
Joined
·
5,650 Posts
It is completely normal for the system to cycle at idle. By frequently I mean if the A/C clutch cycles on and off several times a minute. At idle and about 80 degrees outside with less than 20% relative humidity, a properly charged A/C system should have the clutch engaged for about 1.5 minutes and then off for less than 10 seconds, just for reference. Any higher temperature should have the A/C clutch always engaged at idle. Note that this is with the blower set on MAX. The functioning of the system changes with temperature and humidity.
 

·
Registered
Joined
·
109 Posts
It is completely normal for the system to cycle at idle. By frequently I mean if the A/C clutch cycles on and off several times a minute. At idle and about 80-90 degrees outside with less than 20% relative humidity, a properly charged A/C system should have the clutch engaged for about 1.5 minutes and then off for 5-15 seconds, just for reference. The functioning of the system changes with temperature and humidity.
Yeaaaap. Mine is cycling about 3 times a minute. :)
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #10 ·
Outside temp 97 3-4 % humidity, blower max on max air. Temp coming out of center vent 44-46 degrees. Before adding freon, ac compressor was cycling on 8sec then off 4-5 secs, temp at same vent was ~55 degrees. After freon was added ,comp stayed engaged > than 1.5 min, off for a couple of secs then back on. Interesting to note, when freon level was too low engine idle speed varied about 300-400 rpm's as ac compressor cycled on and off. After freon added rpm didn't change much at all as comp cycled. At freeway driving 70-85 mph, outside temp 99-100, fan speed less than 50%, control set to (normal AC - not max) temp at center vent stayed about 42-45 degrees. Thanks for all your help !! John
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top