Hi all, bought this truck back in March, needs some work, I’m not very mechanically inclined but that was part of the reasoning was getting this truck. My dad took it for a car wash and now the interior cargo lights and glovebox lights don’t work, also the speed sensor has gone bad or knocked out of place (shifts rough, odometer/spedometer not working) we were replacing my battery and I was looking to try and find the issue for the lights and found this mystery wire (with repeater? Not sure) on the drivers side right behind the fuse box, wire coming out of the A post. Tried to do some of my own research but not really sure what it is, any ideas? My guess is maybe it’s the solution to the lights (but I don’t know where it would hook up) or maybe for my drivers side speakers because the wires look similar.

 

The previous owner had an amp in it?
Possibly a light bar or even a trailer battery connection?
Must have been a pretty big amplifier to need a 100 amp fuse
Either way, if you do not need that wire for a power source, I'd remove it

 

It most likely went to a big stereo system because that is the type of fuse they use. Winches draw far more then 100 amps under load and they are usually not fused.

> My dad took it for a car wash and now the interior cargo lights and glovebox lights don’t work
> shifts rough, odometer/spedometer not working

I would guess a door switch got nuked from water spray? Though seeing that aftermarket fuse box just hanging around, I would guess it grounded out and maybe blew fuses, if lucky, or worse melted fusible links.

Pull every ATC/ATO fuse, which might break corrosion, check with a DMM for continuity, replace. Pull and put back all relays.

If still nothing, then pull the bulbs and test the sockets for both + and -. You could check the door pin harness for negative in and then apply (-) out to see if the interior light go on. FWIW: I use fused test leads and start at 5 amp. Do not bother using anything other then Eaton or Little fuses, all the rest are Chinese junk.

 

Pull the fuse, leave the cable for future uh, activities.....like installing an amp again.