'97 F150 4.6L

Hi. I've searched the forums for some hints on my problem with no luck, so here goes:

For the past 1.5 years, I've had a consistent (most days) problem with power to several interior functions disappearing with the following symptoms:

1. Start engine
2. 1-60 seconds after starting engine, an audible click is heard from interior fuse panel (under driver side dash)
3. After click:
3a. Power windows do not go up or down (both sides of vehicle).
3b. Door lights in roof do not work.
3c. Dimmer switch on the left side of the instrument panel will not turn on roof light.
3d. White lights in door (near bottom) do not light up.
3e. Manually switched ceiling lights (Driver side and passenger side) work properly. Also cruise control, instrument cluster lights, cig lighter/power port, windshield wipers, power locks all work OK.
4. This condition persists until the key is switched off.
5. After switching off power, there will be a short (1-3 second) delay and another audible click will sound from the interior fuse panel. At this point, all of the previously mentioned problems are gone and everything works fine.

Some notes:
1. My first suspicion was a faulty relay in the fuse panel. I have replaced the two relays that are labelled (from the owners manual) as being related to power windows and the delay circuit. I don't have the actual fuse panel position numbers but I could get those if that is important. At any rate, this did not fix the problem.

2. This problem seems to be related to ambient temperature. It is more severe in cold weather (below 40 degrees) and persists throughout winter in Michigan. As the temp goes up, the problem happens less and less and it will finally not happen at all when the temp is consistently above 70 degrees. Lately, though, the frequency is increasing even in warmer weather. It has become enough of a bother to try to fix it
3. I have heard mention of a GEM device in some other posts, but I'm not familiar with that and I'm not sure if all of my symptoms are consistent with a bad GEM.

Does anyone here recognize this problem or have any other diagnostic suggestions? Any advice would be greatly appreciated.

Thank You

 

The first thing I would check is the fuse panel in the cab (sounds like you may have already done this)

Just because if it is this, it would cause you the least hassle.

If you can get ahold of the positions great, if not, let me know, and I will photocopy my manual for you.

It seems to me that the temperature effect would not make sense if it were a blown fuse though. It does make sense that it may be something loose, or disconnected. Maybe something rubs... etc.

Also, does this happen when the vehicle is not in motion as well? If not, then I would figure it must be a loose wire, connector, etc.

I really don't know that much, other than the common sense type stuff, I am sure someone more knowledgable will chime in soon.

 

Check for water entry through the windshield into the GEM/Central Junction Box. The windshield most often leaks along the top of the windshield on the driver's side and the bottom corner near the wiper cowl.