Installed msd ignition box and dizzy. Now wires under dash try to get hot

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Dan s

Dan s

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Did this about a month ago and just now have time to fool with. I’m missing something cause the truck I took it out of it worked fine. Now when the motor is running it tries to melt the harness under the dash and the switch will start getting warm. Has anyone run into this.

69 dart 318 is what is in it.
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Factory wiring harness? Sounds like you're overloading it. It doesn't take "much".
 
Is there a change in wire gage?
Where exactly did you mount it?
Check the old under threat wiring for cracked wires.
 
You can troubleshoot this by putting a large wattage bulb in series with the battery ground, such as an 1157 turn filament, or 1156 back up lamp

Turn on the ignition and pull fuses and disconnect components until the bulb goes dimmer. Unplug the VR and unhook the alternator

WHERE EXACTLY did you hook power for the MSD?
 
If the THICK red wire of the MSD box has been incorrectly wired through the ign system, you will probably have some 'hot' wires. This thick wire is supposed to go directly to the bat [+] terminal. Something to check.
 
Nice car & nice colour! Had the same model, loved the shape...
 
Thanks for the response. I’ll check all that today when I get back from the drive line shop. I’ll get some pics of the wireing today also. The only thing different that I done as far as wireing goes is on the motor it came off off I had it wired to a toggle switch and a push button to start. On the car I am trying to use the ignition switch. I probly have it wired wrong. I’ll post back later today. Thanks again.
 
I have a factory k member and rear end if someone is interested. Just pm me
 
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So this what I found today. The back of the volt meter got hot and is probly shot. It is trying to charge at 15 amps. Not sure why
 
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I know it’s a mess. But this is how it’s wired for now till I can figure out the problem
 
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Sorry the pic is upside down. That’s what it’s charging at
 
That is not a voltmeter, it is an ammeter, which is in series from battery to load, meaning, BOTH those wires are HOT at all times and POORLY fused. Only protected by the fuse link in the engine bay.

READ this article for an overview on the how and why of this problem. You do NOT have to bypass this the way they did. Crackedback makes a nice little bypass kit

Catalog

The simplified diagram on that page gives a clear picture of the basic power distro

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The usual culprits are damaged terminals in the bulkhead connector, damage in out and around the ammeter and the wire ends, and in rare cases damage or failure to the "welded splice" which is a few inches from the ammeter on the big black wire, taped up in the harness.
 
You seem to have amps (amperage, current) confused with voltage It is charging at 15V This is commonly caused by voltage drop in the harness. "The path" from battery to VR (refer to the diagram I posted above) is battery---fuse link---through the bulkhead on RED--to and through the ammeter, out on the BLACK--to welded splice---to ignition switch connector--through switch and back out switch connector (ignition "run" dark blue, IGN1) back out through the bulkhead connector---and branch off to underhood loads, the alternator field, the VR, the ignition system, etc etc.

ANY DROP in that path will ADD to charging voltage

Also DROP in the GROUND will cause this. Make CERTAIN battery is WELL grounded to body, and VR is clean and tight to body
 
I would not worry "for now" about the high charging voltage. Don't get sidetracked. Fix the importand stuff--the ammeter problem (the high voltage may fix itself when you do!!) and next the important stuff that doesn't work, hot wiring, etc.
 
This is what started the problem. It has a bad connection so that’s when I switched to the msd box. Do I still need the ballast resistor. I didn’t use any of that in the truck I took it out of. I don’t understand why it started right after I switched.
 
67Dart273 said:
I would not worry "for now" about the high charging voltage. Don't get sidetracked. Fix the importand stuff--the ammeter problem (the high voltage may fix itself when you do!!) and next the important stuff that doesn't work, hot wiring, etc.
Click to expand...

lol. I’m working on it. I really appreciate the advice guys. Wireing is my worst nightmare
 
Hot amp meters from to much current going thru them have caused fires. Somewhere on this forum is a schematic for wiring in a relay triggered connection between the battery or alternator ( @67Dart273 correct me here) and the voltage regulator to limit the overcharging caused by voltage drop. I’ll find it when I get back home and post it.
 
The amp meter post is done for. Spins inside the cluster. I’m just before ordering a complete new harness.
 
So the factory gauge is shot. Can I just unhook and tape it up. Or will that cause more problems
 
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