I keep burning my wires

Question:

I keep having the same problem with my 1952 Chevy pickup even though I have re-done it about five times. The previous owner converted the truck to a 12volt system and I burn up the 10-gauge wire that goes from the battery to the ammeter within seconds of hooking up the battery, which is new. I have confirmed that the proper terminal is the driver’s side terminal, which is behind the negative side of the gauge.

The starter has been rebuilt twice and I have a new starter switch, a foot starter switch. The gauge cluster is tightened down to make sure that it is grounded to the metal dash. I am on my third ammeter gauge. Any help for an old guy who is rapidly getting older would be greatly appreciated.

Answer:

The ammeter in your Chevy truck must be installed in series with the wire that runs between the battery’s positive terminal and the alternator’s output terminal. In other words, the alternator or generator’s output wire should connect to one of the ammeter’s terminals and a wire from the battery’s positive terminal should connect to the ammeter’s other terminal. If the alternator circuit has a shunt resistor then the shunt resistor must be connected in series.

There should be no “negative side” to the gauge. The wire is burning up because there is a short circuit to ground somewhere in the circuit. Physically trace each wire connected to the ammeter to their respective ends.

As stated above, one wire needs to go to the output terminal of the alternator and the other wire needs to go to the positive side of the battery.

If the wires are correctly connected, the alternator doesn’t have an internal short, and the wires don’t have a break in the insulation that’s causing a short, the wire won’t burn.