The AC compressor kicks in only when the brake pedal is pressed and then after like 5 seconds it will disengage again. While this happens, the AC compressor does make whining noises, which could be due to the compressor bearing issue. However, it seems irrelevant to the problem??

I jumped the High pressure switch as well as the cutoff switch but to no avail, but jumping /bypassing the AC compressor relay switches the AC compressor 'ON' permanently, irrespective of the AC button in the cabin.

Need assistance diagnosing the issue. I have a spare AC Compressor with me, would swapping it at this time be any good?

 

If bypassing the relay works, try swapping the ac relay with another relay that is the same part number. Ford uses a ot of the same relays for different things. If that works, then you know the relay is bad. If that doesn't work then you know the wiring for the relay circuit is bad and you'll need to trace it out.

 

Swapping the relay doesn't work. The compressor only kicks in for a second or two when the brake pedal is pressed and then its disengaged again. It does flow cold air when engaged.