A/C help

[Highway Drfter]

Hello friends,
My A/C compressor turns on then off...on then off.
It stays on for about 3 sec. then kicks off... then back on
in about 10 sec. or so.
I checked the coolant level and everything seems in order.
Any ideas?
Thanks!

[jimmytroanoke]

Rapid Cycling is generally Low freon level in system. There is a low pressure cutoff switch on one of the lines. If your system is low, the pressure in the return line drops below the threshold and triggers this switch. It is to protect your compressor. You probably need to add a can of freon, but should use a gauge or have it prof. done

[Highway Drfter]

Hey Jimmy,
Thanks for the reply,
I've located the low press. port on the dryer. I've cheked the freon level. It goes from green(good) when the comp. is off, to low when it turns on for the few seconds. Then it kicks off. However, when I add freon, when the comp. is off the level goes to the red or overfill level. I can't get a steady reading. B/c the cycling on/off Should I keep adding more freon?
I know where the comp. clutch switch/low press shut off is, should I replace this?
Once agian thanks for your help. I live in Fla. As you can imagine it's HOT! All advice is appreciated!

[jimmytroanoke]

Originally Posted by Highway Drfter

Hey Jimmy,
Thanks for the reply,
I've located the low press. port on the dryer. I've cheked the freon level. It goes from green(good) when the comp. is off, to low when it turns on for the few seconds. Then it kicks off. However, when I add freon, when the comp. is off the level goes to the red or overfill level. I can't get a steady reading. B/c the cycling on/off Should I keep adding more freon?
I know where the comp. clutch switch/low press shut off is, should I replace this?
Once agian thanks for your help. I live in Fla. As you can imagine it's HOT! All advice is appreciated!

The gage readings assume that your compressor is running and are meaningless when it is off. As you add the freon, the cycling will get longer and longer. You may have to jumper the low pressure switch to get it to pull the freon out of the can but if you have some cycling going on it should pull it in. Do you have a buddy with some real gages (in PSI) with Hi and low side gages? Easier to tell what is going on that way. You could have a blocked orifice tube causing the high pressure switch to cut it off. You might want to use a can of the freon with dye in it to find any leaks.

[Highway Drfter]

Cool,
Thanks for the info.
My buddy showed me how to jump the switch using a paperclip.
I'll try that and see if I can get the comp. to pull in the coolant.
I'll let you know how it works out.
Thanks again for the help!!!

[manlion]

Hello,
I am having a similar problem. My system shuts down when I hit the gas (under load only). I have checked vacuum lines into passenger compartment. Problem seems to be outside of this area. I have changed the vacuum resovoir canister. The car has auto temp control. I also disconnected my TPS to see if WOT problem. It made no difference with this sensor out of system.

[juliansea]

Highway Drfter]

I have a 1992 Grand Marquis with that EXACT problem. Did you ever discover a fix for it? If so, please let me know what did it. It's hot in VA!

Thanks