View Full Version : Electrical: 12v Draw on battery

07-20-2015, 11:29 PM
57 Commander, 259V8: I have a 12v draw on the battery. The bracket with the turn signal flasher mounted also has 2 fuses. When I pull the fuse farthest from the flasher (the outer of the two fuses), draw disappears. Where shall I begin? The brake light switch bad?

07-21-2015, 12:39 AM
Look for any light that are on including the truck light and glove box light. If no lights are on then lift a battery cable and put an amp meter in line to see how much draw you have. See if the voltage regulator or generator feel warm with the engine off.

When I bought my 50 Champion a year ago I could smell something electrical getting hot. I touched the voltage regulator and it was hot, so I removed the battery cable, then took the regulator in the house to fix it. A new repro regulator and the contacts were way out of alignment as well as not mounted parallel to each other, and the springs were also way out of adjustment. It worked fine once I aligned the contacts and made them parallel then adjusted the springs for the right voltage.

BTW my brake light switch looked brank new, but it was also bad. However it always stayed open rather than being closed.

Skip Lackie
07-21-2015, 09:34 AM
Since the directional signal circuit interrupts the brake lights on one side, you could have a partial short in any of the wiring going to the tail/brake lights or parking lights. You also could have a short in one of the sockets that is allowing the electrons to cross over from one filament of a bulb to the other. This might show up as a weakly lit bulb.

07-21-2015, 10:23 AM
You should have 12 Volts to the brake light switch at all times even with ignition off. The fuse is to protect the circuit.