Rocket Olds

while driving around town I noticed the generator light came on and I looked at my SW votmeter and it was at 16+. No noises or running problems or smells or smoke. I could let off gas and it would sometimes drop to 13+ for a short while then climb back to the 16 as I accelerated back to 40 mph. Is that what I remember on an old 67 chevelle I had with the alternator and it was the diode trio inside the alternator ? or is it a bad alternator? or something else? thanks Mike

stellar

Most likely culprit is the regulator.

stellar

A 67 alternator does not have a trio unless it was replaced with an alt from a later year. Other reasons for over charge are a bad ground, a bad battery or a battery that is low on water, an open or bad connection to the regulator number 3 terminal.

Rocket Olds

thanks for input I will update later. Mike

Rocket Olds

old battery dead and will not charge up! replaced battery with new and same results GEN light stays on, put new regulator on and same issues, GEN light stays on. bought new reconditioned alternator and still same issue. What is next?

Sugar Bear

Was anything done to the car just before this gremlin or did it come about "out of the blue"?

What is the charging voltage across the batt terminals?

What is the voltage with it running from the alt output stud to ground?

If the alternator is unplugged does the light go out?

Check the ground strap from the engine to the firewall...it is on the back of the head if I remember correctly.

Good luck!!!

oldcutlass

It's either a bad regulator or the regulator is not sensing battery voltage and it's in runaway mode.

Rocket Olds

i will check on that list and report back later today, thanks as always Mike

Oldsmaniac

Check gen/alt fuse in fuse panel

Rocket Olds

charging was 12.92 at new battery and 12.87 at new alternator, ground strap tight at both ends. new regulator started to buzz? And noticed that all of a sudden the gen light would flicker and if I revved the engine the GEN light would now go off and then flicker and dim as engine slowed down so I replaced with the new regulator with old and noise went away and light is off and my SW volt gauge reading normal range of 13+. And yes it all started all of a sudden while driving the other day. So bottom line it was bad alternator and battery. Maybe not in that order. But it is working great now! thanks again for the help, Mike