Smoke!!!

[scampbel98]

OK, great...
Started the 124 this morning to take it to work. STarted fine. coughed a little bit. stalled... no biggie.
crank crank, crank... wisp of smoke from under dash... holy shit... what's going on?

Quickly cut ignition. pulled dashpanel... crank - wisp of smoke.. the blue/black lines going to the dash feed are overheating and melting (the large wide white block).

I"m drawing current down that line... but what? I've not done any electrical work or anything other than replace the exhaust manifold recently. I did notice looked like mouse had chewed into some paper on the floor..

Crap.....

Have to open Brad Artiques wiring diagrams now... and maybe look for chewed wiring?

[scampbel98]

BTW: it still wouldn't start - so i'm thinking something in the circuit that feeds the ignition is involved too?
I've disconnected the battery...

[mpollock]

The white connector for the ignition switch seems to be a common problem on Spiders. At some time in it's life before I owned it mine did the same thing - the remnants of the melted connector block are there, and the wires for the starter are crimped together and bypass the block. The original design has the full starter current flowing through the connector and the ignition switch, and the connector isn't up to the task. A bit of corrosion or a loose connection is all it takes to burn the connector. When I go through the electrical system I'm going to put a relay in the circuit so the ignition switch doesn't need to carry the full current.

[scampbel98]

Thanks Mpollack. I'll look there. Mine already had the brown surgery and the ignition switch connector is butchered. Not sure what the ignition circuit and the blue/ black have in common yet. Definitely high current thru it at C22. Will pull fuses first. Hoping alternator isn't back feeding some how

[perthling]

Could be your ignition barrel internals - that's what happened with mine.

[scampbel98]

All,
I could use some help here.. I have electrical skills...

NOw that the dash is torn apart and the consoles removed and the wiper valence removed....
It looks like the blue/black wires that double up on the C22 (big wide 11 pin connector behind the dash were running overcurrent when ignition turned on. Remember, only smokes (actually the wires jumped) when the ignition switch enabled. This was observed with every possible connection removed, fan switch, dash, radio, power window harness.... everything..

So I started undoing some of the electrical tape to trace what went where. Ran the blue/black down to the harness that goes into engine compartment. Start looking for burnt wires, melted electrical tape etc....

There it was... the electric choke connection - which I think *used* to be an anti idle solenoid.... was loose and shorting out on the carb. (that could have been bad)...

My question: how the heck does this short circuit run unprotected to the point that it melts wires?

Off to study Brad Artigue's outstanding wiring diagram.....

[vandor]

There are some circuits that are not protected, like the ignition coil. Other circuits are only partially protected. For example the current for the headlights goes from the alternator to the ignition switch, to the headlight switch, to the column switch, and from there to the fuse box. So only the fuse box to headlight wires are protected by the fuses.