Hey all -

Was given a 94 toyota pickup 3.0L V6 and the wiring is a mess. In my attempt to remove all the bs around the battery, I've found a few wires that I don't recognize. When I ground the negative and attach what I think should be the positive, everything starts smoking. Does anyone know what these cables are and whether I should attach to the positive or negative terminals?

Left wire is coming from the fuse box. Middle (on the washer fluid reservoir) and right I'm assuming are starter and alternator. As soon as that middle wire touches anything, everything starts exploding. It's wild. What am I missing here?

 

Um, well, you’re left with getting a wiring diagram and tracing, if stuff is smoking and getting “wild” I’m not sure I would be doing anything unless your comfortable with what goes to what…..if your not comfortable? Take it somewhere.

So was it all working and you didn’t like the way it looked and took stuff off of stuff? Or was it all hanging there and your just hooking stuff up?? Or was it not running and you’re trying to get it to run. Lots more info is needed here for electrical gurus to jump in…..

 

It was running fine but there was a massive drain on the battery. Replacing every 6 months or so.

So we replaced the alternator yesterday and put in another new battery (starting fresh). When we plugged everything back into the terminals, we saw smoke. So we took everything off.

now we have these three cables. One from the fuse box, and the other 2.

I just want to know what these wires are. That’s it. Fuse box wire goes to… positive? Is that a ground wire that goes to… engine block? And the third is that the alternator wire to positive?

 

Based on my 1991, and from what I can see, the wire with the large lug “in the middle” is the main starter wire that goes to positive. The wire on the left to the fuse block also goes to positive. The seemingly small wire on the right, based on its position against the wheel well should go to the engine block at the front bolt for the motor mount. That goes to negative. I also have a 4th wire that goes from battery negative to the fender near the battery. Hope that helps.

 

What's that relay for in the upper left of your photo?

 

UPDATE: she starts up and sounds good! This wire however, still has no home. If it touches ANYTHING METAL, everything starts smoking. So, for now, it’s wrapped in electricians tape and is off to the side. Going to take it to a YOTA mech Monday and see if they have answers.

Thanks Woodmac 64. Very much appreciated.

 

First, the large gauge wire coming off the battery negative should go down to the engine block, normally bolted to the AC compressor mount, or directly to the block where the mount would go, if the truck doesn't have an AC system.
I put another wire of the same gauge direct to the fender well, in front of the battery, just behind the head light. A lot of systems use the body metal as a ground, and I wanted it to be able to carry all the current it needs to. Is it too big? Yeah, it is overdone a bit, but I hd the wire available, and the ends for it, so what the heck. A 10 GA or 8 GA would probably do the job nicely, but the setup I have seems to work very nicely for me...

Why not jjust follow the mystery wire to where it winds up? Once you know where the other end goes, you know what it is. I would pull the negative lead off the battery while tracing the wire, though. Just to be safe.

Good luck!
Pat☺

 

Sorta looks like the wire that goes onto the insulated bolt on the alternator. Does it trace back to the engine loom?