I have a 1998 f150 4.2L that about 3 months ago began with some quirks in the wipers, dome light, and the chime when key is in the ignition. None of these will work until I drive 6 or 7 miles and the engine warms up. Then they all work fine until the engine cools off - then none work. I have checked all the fuses and relays and all are good. I also removed the dreaded "GEM" thinking it would be rusted or corroded when I took it off. It was clean and bone dry.
Has anyone else had this problem or any ideas on how to fix it? With winter approaching, I'm not sure how far I'll have to drive before they work! Thanks in advance for any help.

 

The only way to track this down is with a voltmeter.
The fuses that supply the Gem also supply other functions.
Look in your fuse lists for those that supply the functions you have issue with.
There you see the other functions.
Do you see some of these other function OD at the same time?
That would tend to narrow down the fault to a heat sensitive location in the engine bay.
It could be a connector on the bottom of the power dist. box.
Good luck.

 

Thank you, Bluegrass. It seems that there is a relay that only controls the items that aren't working. I checked the relay by transferring it to another location in the box and the associated items worked. I also checked all the fuses and they work in other locations in the box.
Is the power distribution box the main one that comes from the battery or the one under the hood that has fuses and relays in it?
I appreciate your help. Thank you!

 

Some relays have fuses that protect them.

You need an owner's manual. If you don't have one you can download it.

http://www.fleet.ford.com/partsandse...owner-manuals/

 

Lucky you.
The main PD is the engine bay.
The other is on the left side of the Dash behind the small panel that comes out below the head light switch assembly.
Good luck.

 

Thanks, glc and Bluegrass. I appreciate the advice. I am stumped by this thing! My thinking is that the fuses and relays must be functioning since everything works once it gets going. I'm trying to check all the connectors - heat makes things expand- possibly they expand enough to get contact once they warm up. With that theory in mind, I'm focusing on the engine bay connectors right now. I have been looking at the owner's manual and I know which relays and fuses are involved. Getting a new voltmeter to check this with. Thanks, again.