So I upgraded to the HEI , no problems there! I also upgraded to the “heavy duty” charging system as described by Dan “the man”. Today as driving back home from the store voltage jumped to over 15. All wires traced and in great shape. Forgot, also upgraded to headlights on relays as well. Anyway, seems my voltage reg is done. I had noticed the infamous flicker came back all of sudden and it has been charging and running fine, then today bam. Am I missing something or did I make a mistake somewhere? It’s a 78 dodge d100 slant six. I do have a factory service manual and have bypassed the ammeter correctly. Anyone ran into this? Also, on eBay there’s a lot of NOS voltage regs for sale. Would that be a better option than a heavy duty adjustable one?

The first thing I would do is swap in a new voltage regulator. Make certain the case gets a good ground and just see if that fixes things. It could be just that simple. If the new VR dies, then start checking your previous work.
jus sayin....

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-MattMan
LEANED & MEAN

If You have a DVOM, see what the V difference is between readings at the batt post, & ign feed at the reg. Poor contacts in the ign sw or any of the terminations will tell the reg the V is too low, & it will respond accordingly. That said, l'm not too concerned about 15V, but the pulsing could be diode issues or reg issues. Check those readings &0grounds to be sure.

Probably a case of new parts being junk. I like to scout eBay and buy new parts that are 30-40 years old. Back when made in China was hardly ever heard. Or seen on packaging

I believe this was the case. I’m trying to find a oem original voltage reg but for now I have it going again. Reseated all the wires, checked with ohmmeter and chevalier voltage drop. All seems great with the new voltage reg. Charging is steady at 14.3 and no more flicker. System seems a lot better. I’m thinking of getting with my engineer at work and build a simple repairable voltage reg system that’s reliable.

Look on eBay for an old niehoff, filko, delco, standard/blue streak, kem brand, echlin, etc, look for old faded shelf worn looking packaging. Some of these brands still exist but in name only, these companies are a shell of their former selves. You want OLD STOCK of these formerly good parts brands.

There’s quite a few on eBay right now. Not sure what all the numbers are but it’s a two prong like what’s in my truck.

This one?

https://www.ebay.com/itm/Mopar-4111990- ... 890.l49292

All mopar regulators from around 71 up take the same VR un til you get new enough to get into engine computer controlled voltage regulation. (Now I'll look at your listing you posted)
Yeah that one would work.
I have a buddy with a 89-90 cummins powered truck, even that takes the same VR as yours would.
He was having charging system issues like crazy, he had replaced the VR once, then the alternator, ok for a while each time. More problems. Another VR. Worked for a while then same problem.
One day at his work they were clearing out old parts for vehicles they no longer had in the fleet any more, (brand new parts mind you, going in the dumpster) and he found a VR like what would work on your truck, and saved it from the dumpster. Lotsa dust on the box. He put that VR on his truck and no more issues, it's been a while since he put that new/old VR on his truck too.

On my own 85, similar issue. I went to a different parts store and bought a VR because the original one had all the potting/varnish melted out of it and running down the firewall. Was still charging ok with the melted one, but I knew it wouldn't be for long. As soon as I plugged in the new one charging was dead.
I had gone to the junkyard for other stuff and while there I grabbed a couple of regulators and mopar ECU boxes from junkyard refugees. My truck is running and charging fine on an unknown age or mileage VR from that junkyard run. And I have a handful of others both new and used just in case I need them.
(Current stock) New parts are crap.

If it is a VR problem, a wrecking yard one would likely do fine, if there's still any around. I had a similar mild overcharging problem on my '83 truck not long ago. I had posted about that. A 3 year old Standard VR had gone goofy. I replaced in with a new Standard VR that I had. No better. I then ordered an OEM VR from Old Car Parts northwest. Considerably cheaper direct from their website than their offering on ebay. Be OCD on grounding the regulator body to firewall. Star washers are good.
From part of my past post:

"I found a Mopar 4111990 VR on Old car parts Northwest's website which I believe was oem on my truck. Only $19.99 ! I had it coast to coast in 3 or 4 days, first class package mail. They had two other Mopar electronic VR's listed for considerably more money. Not sure of the applications for them. OCPNW has the same 411190 VR listed on ebay for $29.95! Mine was quite shop warn. I installed it today and am back to proper charging levels. After a fairly long crank over, It started at 14.6 and dropped to 13.9 after a 30 min. drive, no headlights. Good feeling and I hope I didn't hurt my year old battery too much. Not an AGM, so that helps."

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1982 Dodge D150 ( Ram)
225 with A833OD. 2bbl. Non power brakes

Well working for now. I put a new voltage reg on and it’s stable. I also had 3 spare alternators. 2 were good one bad. I’ll be looking for a rebuild kit that will work. I also need a distribution block so I can fix the battery connections. Does anyone know a good source and good quality one to get? And how does it hook up as well. Thanks