Swapping Ammeter to Voltmeter
Safety Car
Joined: May 2004
Posts: 4,351
Likes: 1,578
From: los altos hills california
I will sidestep the opinion part here. Have a friend who didn't do anything to his 68 ammeter circuit and whenever his electric radiator fans turn on the ammeter goes hugely positive or negative or something way wrong. As was mentioned above, the stock wiring is balanced so the gauge shunt is somehow proportional to current and when you put additional loads in it is very much in error. Since I have the aforementioned fans as well as a steady electric fuel pump draw and I really didn't want to have to think about what might be happening every time the ammeter pegged I decided if I wanted to have things make some sense I would convert to a voltmeter in my 69. Palo Alto Speedometer here converted mine to read zero on the ammeter face at 12 volts and +4 volts at the 40 amp point on my dial. I guess if I put a little green decimal point in there it would be sorta meaningful. Also since my ammeter dial just says "Battery" it can be anything I want it to be.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Chances are that he wired the electric fans into the main power line between the two connecting points for the ammeter. Obviously, that will screw up the readings on the ammeter...depending on whether the fans are on or not.
