Compressor recycling?

[Raptor05121]

At the start of the day when I first start the truck and turn on the A/C, the compressor will kick on and blow nice A/C...for about 10 seconds and then disengage for 10 seconds and then engage on again. It does this until the truck starts moving and then it'll blow really cold air. If I stop moving, it stays cold and the compressor remains working. Could my e-fans be related to this? I read that the condenser has to have air blowing through it...well if I think about it my fans don't turn on when I first start out, but if I stop, the fans are on (with the warmed up engine). How does the clutch sense if the condenser has air blowing through it?

Register today or sign-in to remove these ads!

[fordmaster]

The clutch does not sense air blowing through it. It only senses the condition of pressure between high and low side of compressor by way of some sort of expansion valve. Older Fords had an expansion valve filled with gas that fed back to the compressor. I'm sure now it is an electronically operated switch. If it is really hot and the temp of high pressure gas coming back to the compressor is super high it will continue to run to put as much low pressure liquid out until the high side comes down or equalizes then it will cycle on and off as needed.

It sounds like things are working properly. I don't understand what you think your problem is. If it cycles on and off rapidly it is either a low charge of refrigerant or in some case an over charge.

[Raptor05121]

Originally Posted by fordmaster

The clutch does not sense air blowing through it. It only senses the condition of pressure between high and low side of compressor by way of some sort of expansion valve. Older Fords had an expansion valve filled with gas that fed back to the compressor. I'm sure now it is an electronically operated switch. If it is really hot and the temp of high pressure gas coming back to the compressor is super high it will continue to run to put as much low pressure liquid out until the high side comes down or equalizes then it will cycle on and off as needed.

It sounds like things are working properly. I don't understand what you think your problem is. If it cycles on and off rapidly it is either a low charge of refrigerant or in some case an over charge.

well its not "rapid" but I used to be able to go start my truck, turn on the A/C and come back 5 mins later with the windows freezing over and now if you just start the truck, she wont blow cold unless you are moving or the truck is warmed up (and also the fans come on). I attached a pressure gauge to the low-pressure port and it was in the green, i added a 1/2 can and it went into the yellow..so it cant be a charge.

this isnt a BIG problem, but the signs that it wont blow cold during the initial start up has me worried plus

[fordmaster]

Actually driving your truck is speeding up the compressor. I don't think they put sight glasses in refrigeration lines anymore so unless you know how to use a gauge set you are just guessing. If you do have a sight glass and you can see bubbles...throttle it up some and see if the bubbles decrease. If so it is most likely still low. I hope this helps.

If you are concerned I would let a reliable mechanic check it out. I am familiar with basics of refrigeration but thats where it ends for me. I have went further before and been very sorry. Over charged and ruined a compressor on an older Subaru.