Over-voltage conditions???

[Riverstory]

I have now confirmed that I have an electrical gremlin that I've been chasing for a few weeks. So, I'm seeking somebody that has had the EXACT same issue and what fix resolved the problem.

Completely stock 283 with 3 speed, completely stock wiring harness extensively and meticulously cleaned when completing the recent restoration. Original 37A alternator (rebuilt locally by competent shop) externally regulated. 160 miles since restoration.

The panel truck runs famously 99% of the time. Zero issues . . . until it chugged once under power. Thought it might be fuel, replaced inline fuel filter and brass filter in carb. Ran great and I thought issues were gone . . . until yesterday when it did it again.

I "by luck" saw on a digital gauge (not part of my cluster) that my voltage was 17V. I immediately pulled on headlights and my voltage reduced to 13V. And the truck once again ran stellar.

Took the alternator back to my guy who tested and gave green light. Replaced voltage regulator with new when I restored and once again yesterday.

Ran around town today, zero issues until 20 minutes into the ride, I ran up RPMs in second gear (3500) and watched the voltage climb to 16.7 and the chugging began once again. Backed off the RPMs and the voltage dropped to 14V and the truck ran normal. I have ensured that the alt pulley is the correct size.

Battery is 1 year old and is charged periodically with positive cable disconnected. And is in a charged state (12.7V) during these issues.

ANYBODY??
thanks in advance.

[franken]

Seems like a voltage regulator issue. You might have a look at it and maybe consider an electronic one.
Not related, but make sure you have a fusible link between the battery and the fender junction block.

[Riverstory]

When I purchased the panel, it had the original (adjustable) voltage regulator. When I restored the truck, I replaced with electronic regulator. And when I discovered the over-voltage condition, I replaced the electronic with a new electronic yesterday (cheap insurance).

And I have already added a fusible link.

And I already added 4V fuses to the volt gauge wires.

thanks

[Steeveedee]

High charging voltage "blame" can be placed directly on the voltage regulator. The alternator only puts out what is demanded. Of course, if a low battery is in the system, the voltage will be higher as the alternator compensates for that.

[Riverstory]

I concur that the alternator will put out what is required.

In the manual, it suggests (my interpretation) that the regulator limits voltage to 14.2.

So why doesn't the voltage regulator "limit" the voltage to protect the system? Assuming that the regulator is working properly.

[The Rocknrod]

I would not assume the regulator is working properly since your voltage shows otherwise.

[Riverstory]

moral to the story - while external regulators may look identical on the outside, they are very different on the inside.

Problem solved with different/correct ext reg. Thanks for "pushing" me there. I needed it.

[vince1]

I think I may have had that problem some years ago and it was suggested that it could be a grounding problem.