This morning the battery showed about 6.4 - 6.5 volts. Attempted to start the truck as normal and the starter did not spin over. A jump from a 12 volt battery started the truck right up.

It seems like 6.5v should be enough to start the truck but maybe there's something wrong with the battery that's causing it to die as soon as the starter switch is depressed?

Anyway with the truck was running, I tested the battery and it showed 6.66 volts. Not a good sign. Hahaha.

I know it should probably be around 7.3 or so if the generator is working, but would the voltage be lower on a bad battery? In other words didd a bad generator cause the battery to die or do I need to get a known good battery and then check it then?

Also, I don't think there's a power drain but I will certainly check everything. I do know that a couple times this week the starter seemed to spin a little slower than normal but the truck starts so quickly I didn't think about it too much - colder weather, etc. So the battery could have been dying for a little while.

Is checking voltage at the battery with the truck running the best way to test a generator? Will a bad battery give misleading results on the generator's health?

Last edited by Otto Skorzeny; 11/23/2024 3:24 PM.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)