I am using an MSD 6AL, on a 69 Plymouth. Blaster coil, and MSD Distributor. Car ran great, but yesterday it sputtered and died. I left the ballast resistor in line, as I read in a couple of different places on MSDs website, and in the instructions that it was ok to do so. Doing some trouble shooting, I have voltage everywhere I should, so I figured what the heck, I'll bypass the resistor, and it cranks. So I reconnect the resistor, and it cranks. ???? Examining the resistor, it's broken inside, could this have taken me down? I mean to where the engine wouldn't even turn over?
Posted By: RapidRobert
Re: My MSD ?? - 08/23/08 11:56 PM
The ballast resistor breaking & loosing continuity would certainly kill the eng bec now there's no power to the coil but that wouldn't cause a sudden no crank situation, there's another wiring issue for that.
I wouldn't think the resistor would prevent cranking, but the only change I made was installing a jumper temporarily. I tried to crank it after each and every thing I did. When I installed the jumper, it cranked. I don't like intermittent faults.
Posted By: slantzilla
Re: My MSD ?? - 08/24/08 03:26 AM
Chceck your bulkhead connector in the firewall. I had similar problems that drove me nuts on my Valiant until I pulled the connector apart and cleaned out the corrosion.
Posted By: Alikazam
Re: My MSD ?? - 08/24/08 11:55 AM
You don't have the ballast resistor inline with the coil wires do you? You are using the orange and black wires for the coil and just have the ballast in line with the "switched on +24 V" wire to the MSD box telling it that power is on right, or where? I don't think you want to run the ballast resistor at all with a full MSD ignition unless you have it setup to convert back to factory quickly. The MSD sparks that coil a lot and I think it would be bad for a ballast resistor the amount of cycles being put through it by the MSD.
Well I definitely have a bad ballast resistor, removed it and it's broken, can see it from the back side. It died while running, then wouldn't crank. Put in a new starter relay last year, although that doesn't mean it hasn't gone bad already. Battery is good. Starter relay is for an automatic, but it's a stick shift so that's wired to ground. Could have been a faulty ground there I suppose. The MSD is wired per the directions, have to double check that but it ran fine for about 200 miles. Left the ballast resistor in like MSD says you can, just in case the MSD acted up and I wanted to switch back. I just don't get why jumpering out the resistor allowed the car to crank again. I was trying ti crank the car after every check I made, and that's the one that made the difference. Guess I'll check my ground from the starter relay for the neutral safety switch.
Posted By: Alikazam
Re: My MSD ?? - 11/18/08 01:29 PM
Sorry I've been away, did you get this fixed? I fought problems with my +12V sense line going to the MSD getting grounded out and not letting her start up, especially when she was still hot. Turned out to one time be a chaffed wire touching the intake, then a corroded wire that had high resistance through it that would drop the "sense +12V on" voltage and not let the MSD fire. It is possible with your broken ballast resistor or spade terminals on it with even a little corrosion you were dropping your sense voltage enough that the MSD didn't think the key was "on" so to speak. Hope you got it fixed
Good luck.
P.S. I meant 12 V in my previous post as well... I deal with 24V a lot at work and just auto piloted that voltage when typing, oops.