Output (amperage) is going to be less at lower RPM, the regulator should compensate for that. Are both regulators the same brand?? Did they come from the same factory in China?

 

I’m pretty sure both regs came from the same factory. The one I just got is Transpo part# C8313. Doesn’t say where it is made but the photo on Amazon says MADE IN USA. Transpo does make stuff in US, Canada, China, S America. The first one I got uses part# QS8313. The QS stands fir Quick Start…the name of the company I bought the kit from. He puts his own stamp/logo on the part. I even see in his videos the box that says Transpo on it plus he refers to it as C8313 too. All that said, reviews on these regulators are mixed. Some think they are God-sends, others think they are total crap. I say it’s an electronics part and they’re like a box of chocolates.

What I’m struggling with is this: the gauge needle never budges at 1000+ RPMs. Only time it dances is sub 1000 RPMs. So that tells me the regulator works fine at higher outputs. Yet, the lower I adjust the regulator the steadier the needle is below 1000 RPMs…at least that is a pattern that seems to be emerging (but could be too early to confirm). So this seems to be a contradiction.

NOTE: I’m probably misusing the term output. I refer to that as the voltage reading on the battery.

 

Yeah, alternators is rated in amps output. Its assumed they are generally for a 12 volt system.... And even though the alt is crankin' out 14.7 volts, it may only be able to manage 10 or 20 amps, which is inadequate for computer controlled cars..... but, won't generally set a code, your battery just goes dead over time. (or, the alternator finally takes a royal dump, and stops working altogether. )

If what you describe turns out to be true, then I would be leaning much more heavily toward the regulators being the problem.... In which case, a real Mopar regulator might just solve the issue.

 

That sure seems like the next step HY. I'll probably need a little help finding the mopar reg. I have no idea what reg is for what truck. I see some NOS OEMs on ebay for what appears to be a common regulator for 1970 - 1987 Chrysler. No idea if that is suitable for my 1993 5.2L much less what kind of voltage it pumps out.

For example... https://www.ebay.com/itm/16487818439...UAAOSw-VBgqGKD

 

The stock regulators will be in the neighborhood of 14.5 volts output. (off idle....) So far as I know, Ma Mopar used the same regulator across the board. Not like there are any vehicle specific differences in charging systems in that era...... The one you linked should work just fine, (assuming, of course, that it works at all....) and be a direct replacement for the one you are currently using.

 

I had the truck out again today. Same thing. Needle danced around when I started her up. Danced at the two stop signs in the neighborhood and then steadied right up for the next 37 miles. If that’s what it wants to do I can live with that but I suspect it will wig out again like it has in the past. I should get me one of those NOS regulators (4111990 for the record) for backup. You confirm it’s common stock. If that doesn’t work then I’ll just wait for sumpin’ to give out. But I’m done calling it fixed.

 

Actually, you HAVE fixed it, several times. I would find it somewhat humorous if you were chasing a weak connection down to its source.

 

HY, this one ebay seller has quite a few of these New Old Stock regulators (#4111990). He separates them in two categories (and two corresponding price points). One category are “stamped” (meaning the part number is stamped into the metal case). The other category are “logo” (a sticker with the part number and mopar label on it). He charges less for the stanped ones vs the logo ones. Both are genuine OEM.

Wanna guess what the difference is? Age?

 

Yeah, likely age. Probably cheaper to put a sticker on it, than stamp the number into it.

 

Didn't want to pay the tool and die man to make a new punch.