MSD 6A & Ignition Switch Hot Wire Issue

[Doc Hawk]

Not even sure how to title this goofy issue. I am working at tracking down a few issues in my car wiring. The issue I'm especially keen for input on is an overheat of the + wire (white/red) leading to the ignition switch (behind the key on the steering column).

 

When the car is running, that wire overheats very quickly. After about 5 minutes of running, the wire starts smoking and the car starts running poorly. My guess is that the resistance of the hot wire gets so high that the electronic ignition starts starving for current. BTW, no I did not find this out by running it and saying, "let's see if it gets hot enough to burn up the car." I discovered the hot wire in the first place because of the smoke!

 

Background: the PO did a hack job throughout the car's wiring, so there's no telling what's bypassed or shorted. The car runs and drives. I know I have a constant 3.1A draw on the battery, even with the key off and every single fuse pulled from the main panel. I haven't figured out where to start tracing for a short, since none of the fuses affect the draw condition.

 

Q1) Does that mean the PO bypassed the fuse panel with some line, and it's shorted? Or, are there any suspect lines I should check that are unfused? Where should I start looking for the short? More info below...

 

Also, I am not sure whether or not my charging circuit is working.

 

Q2) How do I check for charging with a multimeter?

 

A CLUE: After much head scratching, I disconnected the stock wire on the negative coil lead. The Blaster II coil is hooked up to an MSD 6A ignition, with a magnetic pickup. I don't know that the stock lead was doing anything for me, because my tach does not work with the 6A. After unhooking that stock coil wire, the white/red wire at the ignition switch still heats up, but only to a "warm" level rather than scorching/plastic melting hot. This is a significant improvement, although I'm still unhappy that the wire gets noticably warm at all.

 

Q3) What could make it so that the stock neg coil lead would affect that ignition switch wire?

 

Q4) Have I hurt anything by disconnecting that stock neg lead? Should I hook it up in a different way? I've seen some people suggest connecting it to the MSD white wire, but MSD says not to.

 

Thanks for any assistance.

[Six_Shooter]

The only wires that should be connected to the coil when using an MSD ignition box is the orange and black wires from the ignition box. The capicitive discharge voltage is high, and will effect other parts in the vehicle if there is anything connected there.

 

The white wire is a "points trigger", that would be used when using a stock ignition box for a trigger or an older points style dizzy.

Whne using a magnetic trigger dizzy and no other ignition module or interface (ECM, GM ignition module, etc), use the purple and green magnetic input.

 

Try checking the items I suggeted in my PMs, diconnect the alternator, starter, etc, untill the current draw drops to an acceptable level.

 

To check to see if the charging system is work is very simple. Set the DMM to voltage, connect each lead to the positive and negitive terminal posts at the battery, note the voltage. start the engine and if it rises to more than 13.6V you're charging. If it rises to less than 13.6V you are still charging but just barely, and the charging system needs repair. If there is no rise or the voltage drops you are not charging at all, and the charging system needs immediate attention.