1971 Elky SS454, stock 63 amp externally regulated alternator, amp gauge in dash, stock wiring. At idle, using a voltmeter on the battery terminals shows 12.7 and goes to 13.2 when revved up. Checking it at the junction block behind the battery shows the same thing. Does this mean my alt is charging ok, and are these figures good enough? The aftermarket volt gauge in the car thats hooked to the fusebox shows 11.8 at idle and goes to 12.5/12.7 when revved. I know some drop here is normal as compared to the seen at batt figures, do these figures look ok? The factory amp gauge does not work, it won't even flicker or move under any circumstances. I don't care about it, but just wanted to be sure that having it inop won't cause a problem like can be caused by the "gen" light not working. I don't know why the amp gauge is inop, and won't go looking unless I have to. Thanks from an electrically challeged TCer!

Could be better. Typical output should be around 14.5v, this would be at the horn relay since that's where the voltage reg is sensing the voltage. It really shouldn't be much less at the battery. Since it comes up a little when you bring up the rpms it's more likely the alt than the regulator.

Those readings aren't real bad but what happens with headlights, heater blower, wipers on. Can the alt maintain the voltage? Probably not at idle but if you bring the rpms up it should be able to. If it can't you run the risk of draining you battery.

If it was me I'd pull the alt and have it bench tested. Maybe has a blown diode.

It's a little on the low side but should be enough to keep it working. This does sound fairly typical for a mechanical regulator.

With my last new external regulator I had the same voltages. I just adjusted the regulator to make it better. You could try too by removing the cover from the regulator and bending the spring tab on the big contact set. This is the set with two fixed contacts around the moving contact. If you make the spring tighter it will charge to a higher voltage and make it looser to charge to a lower voltage.

Peter

Thanks guys. This is the Wells solid state regulator and a new alternator. I have never had any older cars charge higher than 13.5 so I figured it was probably ok.