A/C Problems HELP

[suicidal66]

I have a '01 V-8, What could be causing my AC to be cutting off? I'll start it and everything is fine, after a couple of minutes it switches to vent and then it just keeps switching back and forth. I assume it has nothing tho do with the DCCV because its both sides. I checked the charge and it's good.

I'm in Louisiana and its a little too hot down here for no AC
Somebody Help

 

[Quik LS]

First thing to check is to see if the AC clutch is actually cutting in and out as well.

you have to get into a spot where you can see the pully of the AC compressor spinning - it on the front lower driver's side of the engine.

with the AC off - the belt simply spins the pulley but the clutch disc does not move
with the AC on - the clutch disc is drawn onto the pulley's end and the pulley and clutch spin together. The clutch disc is attached to the compressor shaft and therefore when the disc spins, so does the compressor.

at idle - you need to set the cabin temp low enough to trip the AC (your engine fan should also kick on).

If the clutch disc keeps engaging and then disengaging you may have a worn disc, pulley and or fault magnet. You can buy those parts from a ford dealer and swap them yourself - although it is a bit tricky to do it in-car without pulling the compressor - if you pull the compressor themn you have to re-charge the system.

Another cause may be a low pressure situation. There is a pressure sensor on the condensor. You can test for it by shorting the leads on the pressure sensor on the condensor - if you short them out the system should turn on - and the clutch engage.

So - if your cabin temperature setting should have the AC on, and shorting out the pressure sensor turns it on without issue - you may have to get your system re-charged.

 

[joegr]

Like Quik, I assume that it's not switching between vent and AC, but instead your complaint would be more correctly stated as, "it cools for a while, stops cooling, and then cools for a while again, and so on."

The most common AC problem seems to be failure of the DCCV, but I don't think that's your problem. If the DCCV was acting up, it wouldn't just stop cooling, it would start heating.

Quik's suggestions are good. I suspect that you will find that you are low on R-134a due to a leak somewhere.

 

[suicidal66]

Thanks for the help guys but I'm still having the problem. The clutch disc is spinning the entire time the AC is on. I also had a buddy check the charge and he said it was good and just to double check him I had a shop check it and they told me the same thing. It seems as if it has gotten worse it blows vent temp air most of the time and when it is blowing cool it's not very cool.

Any more advice would be appreciated

 

[joegr]

Did they check the high and low pressures while it was running?

If they are correct about the charge level and you are correct about the clutch always being on, then there should only be two possibilities left.

1. Your AC compressor is failed.
2. Your expansion valve is failed (in the full open position).

Of those two, (1) is the most likely.

 

[tireman]

more info needed

tell us more, when did you have it checked? does it cool on one side of the car and not the other? run the self diagnostic on the datc and check for codes.

 

[suicidal66]

Problem solved. It was all due to misfires caused by leaking VCG jacking up the plugs and coils. I never mentioned I had that problem because I didnt think that wouldve messed with my AC. Changed the gaskets, plugs and coils yesterday and everythings great, best my car has worked in a while.

Thanks for the help fellas!

 

[joegr]

Problem solved. It was all due to misfires caused by leaking VCG jacking up the plugs and coils. I never mentioned I had that problem because I didnt think that wouldve messed with my AC. Changed the gaskets, plugs and coils yesterday and everythings great, best my car has worked in a while.

Thanks for the help fellas!

You should have brought it up. You're not the first one to have AC problems caused by bad coils. The PCM will lock out the AC compressor if the engine is misfiring or overheating. Also, the EMI from the bad coil(s) can cause all sorts of problems in any or all of the other electronics, like the climate control.

 

[suicidal66]

I wish I wouldve, Its been pretty hot down here!