Wiring dilemma (updated diagram)

[93forestpearl]

So the other night I'm leaving work, turn the key, and I get a little flicker on the dash then nothing. Turn the key again and nothing. Its as if I'm not turning the key at all. No ECU, no accessories, no dash lights, nothing. Ok, I thought, my igniton switch finally went. I tried hotwiring it, but no luck. Tested the continuity of the ignition switch in all the positions, and it checks out. I have 12v where I should, and ground where I should.

No fuses are blown in the main or interior fuse boxes. I still have power to things that are not switched, like dome light, hazards, power door locks, and so on. I'm completely baffled.


Here's pics of the wires I've chased so far:








I just don't know if there is someting simple I'm overlooking. I don't think the ignition relay would have such a wide ranging effect, as it controlls power to the injectors, coil, and so on.

[93forestpearl]

Well, I see that everyone is as baffled as I am. Everything I've checked has been good, except one thing- my battery. I tested it with a load and it dropped down to 2.3v. Not good. I'm suprised it could still run the power door locks with the dome/map lights on and the hazards running. I'm gonna get a new one in the next hour, and we'll see where that gets me.

[93forestpearl]

no dice

[rallysam]

So you got the battery was ok?

There's an ignition relay way up under the dash on the driver's side. I forgot where it appears on the diagrams.

[93forestpearl]

Well, there's a short in the system. From FB-25, I've got an 8 ohm resistance to ground, which is no good. That runs the combination meter, mode control panel. (and rear fog light SW, rear fog light relay, headlight washer SW, height control SW, all of which I don't think I have on a '93 L)

As tested from the ignition switch, I was seeing 7.6 ohms to ground, so that would explain why nothing powers up, and why my battery was toast. Alot of current can flow though that little of resistance. Surprisingly, that wire did not appear to have gotten hot, but who knows. That short might not be that strong with a load applied to it.

I'm gonna try it without that pin connected, and see what happens. If I don't have a combination meter, its not the end of the world, but I'll hunt it down evenually. I just need my car back on the road.

[93forestpearl]

Nothing. dammit dammit

This is driving me nuts.

[Legacy777]

Try unplugging all the connectors attached between that section of wiring, and see if that works....if not....it's the harness...

[93forestpearl]

Figured it out. Its the main fuse box. The lead that goes to the main ignition power (BY) will not support a load, even though it reads 12v. I tried to pop a 20A fuse off of it, and no go. I picked up a main box from the JY, but it was even worse. Its jimmy rigged for now, with a separate fuse and wires for the ignition, and the alternator had to be re-run as well.

I may make my own fuse box since I don't need half of that crap in there. Its on the list of roun-tuits.