Hi, I am having some sort of electrical issue with my A.C. When I hit the button the fan pumps faster but clutch on compressor doesn't engage. I stripped a bit of plastic off the hot lead and jumped it directly to hot battery terminal. Clutch engages, A.C. is freezing. Has anyone had a similar issue and knows the fix? Diode, fuse and relay are all working. Thanks for the help. Bill

 

In general if your relay is good then it's usually the system pressure is off and then one of the pressure switches doesn't close and the clutch won't engage. So it's possible either your low side is too low or the high side is too high or one of the sensors is bad, but you need to do more testing to find out which. You can rent a set of gauges from O'Reilly's type places and check out your pressures while you have the clutch jumpered and see what your pressures are at. Or if you have an obd2 scanner you may be able to look at the pressure switch states (ie.an elm 32 adapter and torque app)

 

1. Identify EXACTLY what you are working on, we're not psychic. Year, model, transmission, which climate control system is installed.
2. Scan the PCM for fault codes as certain fault intentionally disable the A/C ssytem
3. Scan the climate control system for faults.

 

I logged into a forum marked 04-08 f150 so I assumed it was realized by everyone reading. I did however forget to mention it's the 5.4 Triton. I would however assume that the systems are extremely similar.. No codes and as I said I jumped the hot lead directly to the battery and the compressor blows ice cold just the way it did at the end of last summer.

 

The PCM controls the AC clutch. The Torque app or ForScan are free and very useful you just need a $10 adapter

In the scan tools you can see the high and low pressure switch and if the clutch is allowed

With Forscan you can run a AC system test with the truck off. And it will cycle through and energize the AC clutch

Look up FordTechMakuloco on youtube he has a video showing you how to do it

 

Do you REALLY want to know how many newbies I've seen obliviously post in the wrong forum?

Any information not explicitly provided is assumed to be in question. That is why questions are asked (but only once). That was your "once"... and you failed.

Good luck.

 

Great, that's kind of what I was thinking. Appreciate the advice.