Mechanics

ELECTRICAL PROBLEM...

2001 Ford F-150 • 130,976 miles

Ok one day several months ago I left both windows down on my truck, single cab, 4.2l v6, 5-speed, 2 wheel drive. And it came a heavy rain. Got in it to head home, started her up, and my radio wouldn't work, my windshield wipers wouldn't work, and my A/C wouldn't blow hot or cold. After some research I figured it was the GEM module, bought a new one and didn't solve a thing. Website said that my year model truck didn't have to be reprogrammed. Idk. Of course this is after I check all the fuses and relays. Both in the junction box and power distribution box under the hood. Everything checked out. Also the ends on the fuse box were in great condition. Also I checked the connectors on the radio, wipers, and door blend actuator, to see if the were getting power and ground, and they are. Even hook the radio directly to the battery and it turned on, so it's not fried. Bought a brand new wiper motor and it still didn't work, even though it's getting power through the wires running to it. And I'm picking up a new door actuator tommorrow. What is the problem here? I'm no certified mechanic by no means, but I understand enough to fix basic stuff. I understand the electrical side of things. I just can't figure this out! Only other thing I can think of is the fuse box circuit got wet. Any way I can test that?
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Johnnybtugboat
July 2, 2013.




I would be glad to help you out, I just need to know what size engine is in your truck?
4.2
4.6
5.4

Sean

Seangrant00
Jul 2, 2013.
Oh sorry I just reread it.

First thing I would do is turn on the ignition to run, and check for power on the fuse box. You can use a voltmeter and check the top of the fuses for power.

Sean

Seangrant00
Jul 2, 2013.
Hey Sean, So I did what you said and checked all the fuses, plus took relays out and checked where they go in at. On the fuse box under the dash I found that fuses 5.6.8.11.16.18.26.27.28. Had no power. Now fuse 20 only showed 4.57v. And fuse 21 only showed 0.03v. All others showed around 12v. Now on the power distribution box, I found that fuses, 19.20.502 had no power. Plus relays, 201.202.203.207 had no power. All others showed about 12v. I guess I did that right, took my multimeter and grounded the black lead, then took red lead to fuses. Set it to 20v. If I should test it another way please let me know. Also just to let you know you can find the fuse diagram at motorcraftservice. Com. What would cause them fuses and relays not to get power? I know that in the fuse box, it has a circuit board in there. Maybe water got in there and fried a few of the circuits? Idk. I'm stumped. Why I like working on my 1982 Chevy. Much simpler.

Tiny
Johnnybtugboat
Jul 3, 2013.
Well it sounds like you are getting power to both the fuse box, junction box, and relays so that's good. Some of those fuses are ran off of relays so they may not have power just off the ignition alone and some do nothing. I would suggest next making sure the grounds are all secure and tight. This also could be related to the bad circuit board as you suggested. It also could be a bad fuse block. You tested them correctly. The fuses with no power, did you pull them all out and check to see if they were blown? Is the truck running alright besides the accessory problems?

Sean

Seangrant00
Jul 3, 2013.
Thanks for the quick reply Sean. Yes all the fuses are good. Pulled everyone of them out. I've checked several grounds around the truck and they are ok, plus the ground wires running to the wiper motor, radio and AC control all are good. The truck runs fine. Or the same as it did before this happened. There's a small vacuum leak on one the head gasket and I haven't had time to fix that yet. But it runs ok. Honestly the fuse block is the only thing I can think is bad. But the connectors on it are in good condition, no corrosion. I'm guessing that when it rained water got on the fuse block and damaged it. Are there any other things I should check before buying a new fuse block?

Tiny
Johnnybtugboat
Jul 3, 2013.
It sounds like you have narrowed it down to that. You have power to the fuse block and all went out right after the rain storm, so I would start there and let me know how it turns out.

Sean
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Seangrant00
Jul 3, 2013.
Ok thanks. I hate having to buy one, pretty expensive. When I have time to install a new one I'll let you know if it solves anything. Thanks for all the advice.

Tiny
Johnnybtugboat
Jul 3, 2013.
You might try a junk yard too.
Sounds good,

Sean

Seangrant00
Jul 3, 2013.

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