Runaway voltage?

[Perry Pessia]

I have a small subwoofer in the car, and when I accelerate the subwoofer quits. As soon as I let off the gas and coast, it comes back on.

If I'm parked with the engine running, the sub doesn't malfunction regardless of RPM.

I'm wondering if the voltage regulator is shot. I had a problem with the turn signals speeding up with engine speed as well.

I'm guessing that the subwoofer is trying to protect itself and shutting off with the voltage being too high. What's the best place to check voltage?

The car is a '59 coupe, converted to 12V decades ago.

Thanks.

[Perry Pessia]

Okay, I checked the voltage at the battery just now. 12.5 or so when idling, up to 16.5 when revving to about 2500 or so.

Thanks.

[Alan Hall]

That does sound high, I think with a 12v system, regulator should limit to around 14v.

[David Jones]

The Bosch electronic voltage regulators are cheap and more reliable than their mechanical forebears. Buy one and fix the problem probably forever.
https://www.amazon.com/Bosch-30019-Volt ... B00QXWYU3C

[Perry Pessia]

Thank you, David. I just ordered one.

Perry

[Martin Benade]

I just installed one yesterday, it looks silly but does the job. Beware, I am pretty sure the entire cover of it is connected to the charging current from the generator. It's probably a heat sink.

[David Jones]

Martin is correct. The cover is at 12 volt +ve. Make sure there is nothing that can contact it and ground it out or there may be a meltdown or more.

[Perry Pessia]

Installed it yesterday, works perfectly. Thanks again.