Smoke = Bad news, Fried ignition wiring -- why? Options

[BMartin914]

As I went to drive the 914 last night, I started it up (started fine) pulled it out of the garage and let it idle while I closed up. Got in turned on the lights and started to check and make sure my lights were working, signals, etc. As I try the left signal, it goes out, then the lights and I notice smoke billowing out from behind the dash. I turn it off and push it inside, take the lower part of thedash apart and find the ignition wiring fried and the key is VERY hard to turn in the ignition.

This week, I noticed a broken ground in my left tail light, I took it apart and reworked the post with a small screw/nut and a new lead to the ground connection. I can't understand how this could have caused the wiring to fry, but I know it was probably a contributing factor. The light is grounded and works so I don't understand what the problem might be.

My left marker/rear light fuse is blowing again and agian and I thought that the broken ground wire was the problem -- no dice. I don't see any broken wires or bad connections and I have traced all of the wire I can get to from the fuse box.

Anyone have any ideas what the problem could be here?

Thanks

Ben

[McMark]

The key not turning sounds like a melted ignition switch (the plastic part). Take off your steering wheel, take off the knee pad on the dash, unplug the connectors on the bottom of the steering column, remove the four screws that hold the turn signal switch assembly into place, then the two screws that hold the ignition switch cover into place, and finally remove the ignition switch.

[BMartin914]

The switch is definitely melted, I know that. I wonder what caused the wiring to burn and the switch to melt.

Switch malfunction? Current flow issue?

[brant]

Ben,

on the wire that you grounded, was it absolutely a ground wire that was supposed to be whole but just broke?

after you reconnected it, did you start the car or turn the ignition on or verify that it was not shorting?

I'm just trying to rule out that wire is all.
I'm sure you did everything correctly.
a few of us have been in your shoes.
I was driving one day and hit a bump and had that same magic smoke pour out from under my dash.

my guess is that your previous fuse blowing problem is the same thing that caused the wire and switch to burn but it just finally got bad enough to rear its ugly head...

I'm betting the wire you attatched in the trunk is what you thought and that this is unrelated....

The good news is that now that you've half started a fire, you will be fixing it... and now that its burned off the insulation due to shorting out with something, it will be easier to trace and find out where the short is...

When this happened to me I ended up pulling the console and lower dash and spending a few hours on my back tracing the whole burnt wire. I can't remember where mine was shorting, but once I found it I then replaced the whole burnt section with a new piece of wire......

hang in there
You'll find that short
brant

[BMartin914]

The ground wire is inside the tail light (brown wire, female end, connects to male plug on backside of taillight). It was not completely broken, but hanging by a thread where the wire meets the lead that connects to the post -- loose enough that it basically fell off in my hand when I pulled a little.

When I put the car back together, I put in a new fuse and checked to see if I had fixed the problem. The fuse blew, so no the problem wasn't fixed, but then I checked the brake lights and they both worked as did the signals -- but still no tail or marker light

I wonder why the IGNITION switch burned though. It seems not at all related to the rear light or front marker fuse.

I guess the next step is to cut off the sheathing on the harness and try to trace every inch of all of the effected wires.

Ben

[rhodyguy]

before you cut the harness, make up some big extension leads you can hook up to your multimeter. i made some that were about 6' long when i had a continuity problem.

[brant]

I think the next step is to get out the haynes manual and trace all of the items on paper that connect to that blown fuse....

then pull the ignition switch out and start on the wiring loom right there where it plugs to the switch.

cross reference and see if any of the wires right there (the burned ones) also tie into the switch that blows or the sub system that keeps blowing that fuse...

next follow those wires (they are taped together, but not inside of a plastic sheath mostly) and expecially physically trace out the burned wires...

use the book alot.
get comfortable and familiar with the wiring diagram and all of the sub sytems you are touching and tracing...

I can't even guess at this point, but probably its tied into that fuse.... and one of a dozen things that is powered by that fuse.

brant

[BMartin914]

Thanks for the advice.

I know what I'll be doing this weekend (IMG:style_emoticons/default/wink.gif)

I was hoping that I wouldn't have to do any work until AFTER snow...oh well.

Ben