Leaky Voltage Regulator

69 Charger 440 with the Mopar electronic ignition conversion. This setup came with the 4 prong ballast resistor. I recently noticed that the VR is dripping down the firewall. Still runs fine, but what gives with that?

Not uncommon. Some can be a sticky mess.

is there an epoxy that can be added over the potting material that could possibly stop that from happening ?

It is going to ruin your paint if you don't change it. There are potting compounds, not sure if you need to remove the old though. It is a pain digging it out.

Is it the voltage regulator or the ign module that is leaking, never seen a V reg leak ?, seen MANY modules get hot & leak

Seen both do it. More so on the ecu though

VR!

Have you checked the alternator output and voltage at the battery? Should be within .2 - .5 V or less.
How hot is the regulator getting?
Is it near a heat source?

sounds like bad grounding on that regulator

The voltage regulator only handles field current not output. I have seen VR potting liquify. It is from age not heat. Heck it can be 30 to 54yrs old.

Not totally agreeing with the age vs heat thing. I had a couple NOS ECU`s in a hot attic and they leaked out. I had others in the garage where it was cooler and they never leaked out.

I put on a new resto VR, small leak down firewall initially, cleaned that off, and it never did it again.
It was weird, like it had to cure the goop.

sounds like you also upgraded your charging system to the 70 up ?? If not there isn't anything that would leak from a 69 down VR ???

How hot does your attic get? Certainly high heat can lead to premature break down of the potting. But I have seen plenty of ECU leak out stored in cool cabinets. So to imply as long as they don't get hot they will last is wrong.

In his case we are taking about electronic VR which only handles about 2.5amp of field current. Also the notion that loss of a ground cause this is not correct either. Losing VR ground means NO field current, and low no alternator output.

If it truly was "just" heat you would see a potting leak or hole in the vicinity of the power transistor that generates the heat. Yet plenty of ECU and VR to a lesser extent have all the potting go soft.

Flex Seal
https://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/3123397/Searchpage/1/Main/255481/Words/%2Bflex+%2Bseal/Search/true/re-ignition-box-voltage-regulator-potting-material.html#Post3123397
https://www.forbbodiesonly.com/moparforum/threads/sticky-goo-coming-out-of-orange-box.198163/page-2

Just saying the NOS ones I had in my attic where it gets very hot at times that they both got soft and sticky. I had them for just a few years and they were all fine when I bought them. They were 40 plus year old NOS. So you tell me what happened? The other two are fine.