Problems with my 04

[Christy Beck]

OK my name is Christy and i own a 2004 ford explorer 4.6 Eddie Bauer edition 4X4. First i was getting this knocking sound in my dash which quit after a few weeks (even though my ac was still blowing extremely cold) then whenever i let off my gas pedal before applying my brake i started getting this strong hesitation noise and feel which has continued to get worse. Well now my compressor wont engage but is still full of gas, Ive got power everywhere except from my fuse box to my compressor and read where my wire could be frayed where it runs under my oil filter drain channel. My main thing is should i go ahead and pull the wiring harness that runs to the compressor, started, and the oil pressure sending unit and see if there is a raw spot in the wire? then secondly can someone please tell me if that sound when letting off the gas is actually my rear end or possibly my transmission starting to go? i don't want to spend a ton of money i don't have in a vehicle that's going to keep throwing more things in the way as i fix them if i can just go ahead and just trade it as is. My car has less then 175K and i just want a few opinions to help me make up my mind.
yours truly, Ms Mechanic of the south lol Christy
UPDATE: checked the harness for my compressor but theres no frayed wires but still no power from compressor to fuse box under hood. compressor not engaging and getting nothing but hot air

 

[Drewmcg]

I'm confused. What would an A/C compressor have to do with the transmission? Maybe you're just low on freon? Whatever driveability issue you're trying to describe is most likely a separate issue.