I recently purchased a 2000 F150 Regular Cab Work Series with the 4.2 V6 4x4 and an automatic transmission. It has what seems to be an electrical issue where the speedometer and gauges come in and out seemingly at random. All of my fuses are good with the exception of Fuse 1 in the fuse box under the steering wheel, which will blow every time I put a new one in. It seems like there is a short in the wiring for the radio? However Fuse 1 is supposed to control only the audio, and I'm not sure why that would be an issue with the gauges.

When they come on, everything seems to work just fine. Also, even when they go out and I have the headlights on, both the gauges and the car stereo will be backlit with the green glow.

When I turn put the key in the run position, the gauges will come on and remain on for a random amount of time after I start the engine, then will go out and come on at random. When the gauges go out so will my check engine light (code P0460).

Any help would be greatly appreciated! Thanks!

 

Treat the fuse F1 issue separately. Pull the radio (and CD changer, if it has one) out and disconnect it and see if the short circuit goes away. If it does, the short is internal to what you disconnected. If not, look for any hack wiring jobs from some previous owner.

The cluster and dash illumination function is independent from any of the the other functions so it's not notable as related to any of the other faults.

What is notable is the intermittent operation of the cluster's electronics. Usually, this is due to a failing connector or a cracked/cold solder joint on the wiring harness connector that feeds power to the cluster.

Pull the instrument cluster out and very carefully (use a magnifying glass, if necessary) and inspect pin #2 of connector C236 looking for a pushed/damaged pin or a cracked solder joint. C236 is a white rectangular 20-pin connector with pin #2 being a red/lt green wire that is supposed to be HOT IN START OR RUN. Repair/resolder as indicated. There are other possibilities, this is the most common.

The CEL with the attendant P0460 is a third, separate issue. That DTC indicates that the PCM is receiving an illogical input from the fuel level sender located in the fuel tank. There are a number of electrical or mechanical causes for this concern.

 

Thank for the suggestion! It actually turns out it seemed to be my alternator overcharging my battery and messing with the gauges and stereo. I should have considered the fact that they worked while key was in accessory position but went out after cranking the engine more heavily. I swapped the failing alternator and everything seems to be going alright so far!

 

Interesting!

Thanks for following up.