1993 Ford Explorer XLT, Possible electrical problem

[Liam Moonan]

Hi, recently I noticed a bunch of small funky stuff going on with my 1993 Ford Explorer XLT, and I have a feeling that they are all connected to one central problem. I have checked all the fuses and relays and nothing seems too out of the ordinary. I have a feeling there may be a short somewhere, but I'm not exactly sure where. I'm just going to list the problems I'm experiencing: 4x4 switch on dash not working, fuel gauge not accurate at all, power mirrors don't function, under hood lamp not working (even after checking fuse and changing bulb). I also noticed that the "anti-theft" light on the dash does not turn on or flash. It's an old car and I'm the second or third owner, so anything is the possible cause for these problems. I also discovered an unplugged plug in the engine compartment, and I'll try to attach a picture of that. Any help at all is greatly appreciated, just want someone to point me in the right direction.

Thanks,
Liam

 

[Rick]

I believe the plug is a test port for an ABS brake scanner.

The other issues may be related to bad grounds between the body, frame and engine. Be sure the braided wire straps are in place between the body and frame and that the mounting points are not corroded. I think there is one at the firewall and another at one of the body mounts. It's been awhile since I've looked so I can't tell you exactly where they are. Same goes for the battery grounds.

If that isn't it I think you will have to trace each problem individually. The fuel gauge issue could be caused by a corroded sensor that's built onto the in tank fuel pump.

 

[2stroke]

I agree. I don't have the diagram in front of me, but I doubt all those have related positive wires. I am going to go bad ground(s).

 

[Liam Moonan]

Thanks for the responses. I spent my weekend tracking down every last ground wire in the engine compartment and cleaning the bolts, grounding surface, and the wire contacts. A majority of them were green with corrosion, but I cleaned all the grounding surfaces just to be safe. Unfortunately, nothing happened. I did some research and found that on the 1993 models, there was an issue with the grounding wire in the rubber boot in the door hinge area getting cut, but that would mean the power windows wouldn't work (and mine work just fine). So I was wondering if there are any grounding points inside the dash, because I remember the previous owner telling me there was a problem with the radio wiring in the back of the radio and how it will cut out once in a while. So I wonder if he went in there and messed around with the wiring and screwed something up, which might explain the 4x4 switch and the anti-theft system. As for the other problems, they must be individual? YouTube told me that the gas gauge might not work because of a faulty anti-slosh chip in the dash, and I remember now that the previous owner did say years ago they had to bring it to the dealer because someone swiped the driver's mirror, and get it replaced. The dealership possibly connected it all wrong (?). I'll have to check that stuff out. As for fuses, I pulled every last one and inspected them, and they were all fine. It is possible I missed some ground points in the engine compartment, but I got the one on the firewall, the two on the driver's fender, the one tp the right of the radiator, and the two on the passenger fender. I honestly have no clue lol, I'm not that great with electronics so any help is appreciated.
Thanks,
Liam

 

[Liam Moonan]

UPDATE: I believe I have found the possible culprit for all these issues. This afternoon I dropped my wallet down by the pedals, and I spotted three cut wires, 2 are red, and a black ground wire connected to the dashboard frame, but there might be others. I got so mad when I saw these lol. I don't know if these are supposed to be cut, but my guess is they are somehow connected to the anti-theft system, and possibly the power mirrors? If anyone can identify these wires, that'd be great. And where are they supposed to connect to? And why were they cut? I couldn't find them in any diagrams. Any help is appreciated. Here are the pictures: