Jtb327

Thanks for that link to the service manuals. Definitely a ton of good info there. I did some more experimenting, and it seems like giving my terminals a thorough cleaning helped with most of the heat. I've installed the new switch for now, and while it gets a little warm, it is nowhere near the temps it was reaching before. Certainly not melting the plug now. The harness runs through the fender and then to both fuse/relay boxes under the hood, so should be pretty easy to keep an eye on things downstream. So for now, I'm hoping the problem was just old wires and bad connections. Thanks again for the input! If the truck goes up in smoke, I'll be sure to post pictures.

Thought I should add that the car and all accessories can be turned on indefinitely without a problem. It is within seconds of actually starting the car that the wires/switch get hot.

Hey everybody! I've been lurking on here for quite some time, and the forum has helped me fix a good handful of problems on my 99' Qx4. I finally found something that's kinda got me stumped, so I figured I'd put it out there and see if anyone has any advice. In short, my problem is that the wires leading from the ignition switch are getting hot. Like, hot enough to melt the harness plug and completely fry the switch. Originally, I thought the heat was just coming from the bad connections of the worn out switch. Naturally, it's not that simple. I've got a new switch coming in the mail tomorrow, but for the time being, I had hardwired the various wires in the harness so I could still drive this week. First, I connected everything directly to the constant power in the harness. I hooked it all up to a switch (The starter is on its own switch) which got ridiculously hot to the point that the plastic was smelling burnt and the electrical tape started to smoke. I figured this was due overloading the wires/switch, so found the hottest wire and ran another switch to direct power from the battery. Now every wire stays cold except for the one leading to the wire labeled ign1. I cleaned my terminals, cleaned and checked my grounds, and tightened everything up on the battery end in case that was the problem. All the fuses and relays seem to be fine, so I've ruled that out too. I experimented with various combinations of switches and directly connecting wires, and each time the source of the heat seems to move to the "weakest" point of the system. Everything I've used is 16 gauge wire, so I don't think that's the problem. I followed the wire as far as I could from the plug to under the dash and couldn't find anywhere there would be a short in the system. So my question is A. Where all does this wire go? B. Is there something I'm missing that would cause this much heat in the wires? Thanks in advance for whatever advice you can give!