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Author Topic: Bouncing Alt/ Volt Gauges  (Read 2281 times)


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Bouncing Alt/ Volt Gauges
« on: September 25, 2014, 02:12:29 PM »
I'm kinda baffled on this situation and have been stymied by this issue.
I've come to you for parts for a last few years now. My most recent order was a couple of your high amp stator kits for the "old school" Chrysler alternator.
I've owned my truck now for almost 41 years. In fact, I ordered it from Dodge back in August '73. On an recent off road excursion outside of 29 Palms, California, a few months back, my ignition just failed on me. I did all the usual diagnostics, including testing the MSD box as per their handbook. And the test pointed to their box. I've been running that same MSD 6A for over 19 years without issues. So I figured "it lived a good life", and ordered a new one and threw the old one away. I installed the new one... nothing. I don't normally throw parts at a problem. Usually.
Upon further digging, my coil tested bad. Replaced it... instant start up. That coil had been on there for at least 200,000 miles, so no big deal. And thinking back, I had a ignition failure months prior to this event. And replaced the pick up coil and things worked well until I was stranded in 29 Palms. In years past... it always was the pick up coil.
Well, this finally leads to my problem. Since this event happened, my charging system seems to be on a trampoline. It pulses the charge at idle so much, the Alt and Volt gauges are constantly bouncing. The head lights and dash lights flicker. Above idle, at a higher rpm, it isn't quite as bad, but it's still there. I know my charging system is up to par. I've rebuilt my alternators (I always have a spare) not long ago with your upgraded 100+ amp stator, new diode packs, bearings and brushes from you guys. All the charging system wires have been redone in the past few years. With a 8 gauge upgrade to the main feed off of the alternator. All the old bulkhead connections have been replaced or highly maintained. The voltage regulator was replaced with an adjustable one... Again from you guys. Just in case.  The battery is less than 2 years old. It's an Optima- no leaker. This was all working fine until the change over to the new MSD 6A box.
I called MSD Tech. They said I have a "floating ground".  And I needed to run a good ground wire over to the passenger side head. Okay. I NEVER had this issue in the past... at all. Well, maybe when I was running a low amp stock alternator years ago.
So I ran a 8 gauge ground wire, from the battery, over to an intake bolt where the coil also mounts to. Still the pulsing charge.
I recently wrote to the tech guru at Mopar Action mag. He suggested that my bridge rectifier/ diode pack was burnt. Change and see. I also tested them according to the FSM... all was good. I feel it's the new box from MSD causing this. I even put resisters on the main 12 volt power feed to the MSD box thinking that might stop the reverse signal back into the system... a shot in the dark. Same results.

I've looked at your piggy-back remote mounted diode boxes. Could this be an answer?
If you have time to waste, here's the story of my truck. 
Also, there is a few other people over there in those forums with the same issue as mine, after they put on a new MSD box. What's up with that? Any other suggestions?
And thank you very much for your time. Kinda baffled here.

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Bouncing Alt/ Volt Gauges
« on: September 25, 2014, 02:12:29 PM »