Hello folks. I'm having a issue with my AC. I took the motor out myself to put in a crank kit and when I put it back in I didn't recharge ac for a month or so but upon recharging it is now cycling on and off quickly. It will cycle on for 5 seconds and off for 5 seconds over and over. I know it has enough refrigerant and I can feel it trying to get cold but will not stay engaged long enough to cool off. Any ideas? I'm thinking it could be a relay but really not sure. Any advice is much appreciated thanks guys

 

First check the power at the compressor, put a volt meter or test light on the two wires on compressor, leave compressor hooked up and engine idling, it will have 12volts(13.5v) when compressor should be on.
If the voltage is cycling on and off then there is a problem with the pressure in the system.
If voltage stays on but compressor cycles off the field coil or air gap on compressor is the problem.

If you disconnected the lines and didn't plug them, then there is probably moisture in the system, and that can cause a plug.
You may need to vacuum out the system and replace the drier as it has absorbed too much moisture.

The pressure switches detect high pressure after gasses are compressed, this prevents lines from exploding, and low pressure switch when refrigerant is low, this prevents compressor running dry and burning up.

The gases are compressed which heats them up, this is the high pressure side, they are then allowed to decompress in the cab which causes the lines to cool rapidly, even freeze on the outside, this is the low pressure side.

 

hey man, I know that this post is a million years old but, did you ever manage to figure this issue out? We just got my wife an 07 Ranger and it’s doing the exact same thing. When defrost or AC is on, every five seconds the idle surges and the compressor clicks on and the clutch spins. Turn AC or defrost off and it stops....what the hell is going on? SOS!

thanks in advance

 

AC compressor should come on in ALL climate control settings except OFF and VENT
The AC is used to DRY the air in the cab in winter and cool the air in the cab in summer
In winter it doesn't need to "cool" the air, just DRY it, so it will cycle on and off more than in the summer when it needs to cool the air as well

You can also have an AC issue, low or high pressure in the system if it seems to cycle too fast, how fast is too fast?, stop at an AC shop and ask

 

thanks for the response. I understand that the AC is used to dry the air in defrost mode as well. What I don’t understand is why it clicks on every five seconds and the rpm’s surge with it because it’s under load. Does it in park, in gear while driving, while stopped.
I don’t think that it’s suppose to click on and off every five seconds while your engine revs up and down. Seems wild. Unless that’s what it’s suppose to do? Never had a vehicle do that before. Seems to be a common problem with these trucks and f150’s but, nobody seems to have a solution.

Anyways, “quick cycling” is what it’s called and often times will happen when the Freon is low so, I charged her AC last night and then reset her computer to see if it would forget any bad habits that it picked up. We’ll see if that did the trick.

 

Did you test the pressure in the system or just add refrigerant?

If you have a fast cycling compressor then something is wrong, so you test the system to see what it is

If you just want to guess I am up for that too
You can replace the low and high pressure switches
Then the AC Clutch relay
Then replace compressor clutch/pulley

Next is, unfortunately, the computer, it controls the AC compressor clutch relay

RPMs go up and down in response to AC Compressor going off and on, computer does that

Years ago Fords did have a common issue with AC Clutch coil, an "air gap" issue
But I haven't seen much on your described issue recently
AC issues are common to any vehicle with AC, sop that part of it would be common complaint but not Ford specific, lol

 

really do appreciate the info!!!!

thanks for all that.

 

yes. I tested the pressure in the system and it was really low and the AC blew warm so, that told me that it needed to be refilled. Wasn’t just a wild guess and throwing money at the thing for fun. Pressure is good now and it blows nice and cold but, it’s still quick cycling.

always start with the most obvious and simple fixes first right?

didn’t do the trick, the problem is still there so, onto the next thing...