Took my 41 to our local car show today, first show after 15 years of storage.

Anyway, the alternator problem is on my 85 c10. Voltage was reading low on the gauge so I went crazy with the multimeter and could never get over 12.5 volts even testing the output from the alternator and chassis ground.

So I replaced the alternator with a rebuilt one from O’Reilly’s it had the same problem for the first five minutes then magically started outputting 14 volts and I figured whatever it’s good now. Drove to work good voltage, time to come home gauge is red multimeter is at 12.4.

I have even pulled the brand-new optima out of my other car to rule out the battery. And the regulator is built in on these alternators.

Any advice on what to try next? If I can’t come up with anything else I’ll go get a new rebuilt alternator and swap it in the parking lot since I’m under five minutes wrenching time now for the job.