2006 F-150 STX 4.2 single cab, When I have fuse 14 in my speedometer doesn’t work, neither does my temp gauge, a/c compressor, and my dash lights up like crazy with multiple different lights(battery, check engine, wrench). When I plug in the scan tool it says there is an error connecting. BUT with fuse 14 out, everything except the a/c compressor works. Now that was fine for a day or so until yesterday when I would hold down the brake pedal it makes A ding all the lights come one and the temp gauge and speedo both drop to zero just like if fuse 14 is in. But the second I let off the brake it all comes back on and the lights go away. Yes I’ve plugged the scan tool up with fuse 14 out and it shows nothing. I have no check lights with the fuse out.
Fuse 14 controls-
Back-up lamp and Daytime Running
Lamps (DRL) relay coil, A/C pressure
switch, Redundant speed control
switch, Heated PCV (5.4L), Trailer
tow back-up lamps relay coil, ABS,
Reverse park aid, EC mirror

 

Check the ground for those items that are powered off of fuse 14. It sounds like the ground is open and the circuits are grounding back through another circuit.