I have my '73 running, and it dosen't seem to charge the battery. It charged fine at first, but then I drove the car about 30 miles, and something messed up. The Tach is real jittery. It won't go below 1,000 RPM when the car is idling (600 RPM), and when you rev it up, the needle moves real slugish and first and then just jumps up real fast to over 4,000 RPM even though I am not revving the car that high. The tach is verified working fine in two other cars, so it is something electrical. I am getting 14.68 volts at the alternator, which is charging. The voltage at the battery jumps around a little between 11 and 14 volts while the car is idleing. All the lights in the car are very dim at idle, and brighten up more then usual when you rev the car up. My first thought is the voltage regulator. I don't know anything about the regulator, it is the same one that has been on the car since the early 90's at least. The car has been sitting since 1992, in very hot and humid South Carolina. I have checked for and cleaned any corrosion on all the terminals in that area, and checked the wires them selves for continuity to be sure nothing is shorted. Just want some more opinions before I start throwing parts at it.
I just checked the voltage while having someone rev the car to about 2,000 RPM. The voltage is jumping back and forth between 15.8 and 19 volts at the battery. The battery dosen't seem to want to hold a charge anymore, either. I put the battery on a charger and charged it back up. Car started right up one time, let it run for a few seconds, then shut it off. Tried to restart it a few seconds later, and the solenoid just clicks as if the battery is dead. Measured 12.36 volts at the battery with the car not running, and it drops down to around 10.5 volts when you turn the headlights on with it not running. I guess I'll go get another voltage regulator and battery and see what happens. Good thing the battery has 2 year free replacement.
Jamie; check to see if that tach has an 8cyl setting. That would make it read low (your '73 is still a 6cyl, right?).
