A 6-volt negative ground, 6-volt positive ground, what does that mean? If you are confused, don’t feel bad. You’re in good company. Ben Franklin labeled "resinous electricity" as negative, and "vitreous electricity" as positive. As a result, we must name the electric currents in metals as flows of NEGATIVE charge rather than positive charge. Ben would have said electrons are positive.
So how does this apply to my car? I’m not driving a kite. A 6-volt positive ground system runs the positive side of the battery to the frame of the car, causing the frame and chassis to carry the current (this was thought to reduce corrosion). When an accessory is wired back to the ground side of the battery, it completes the circuit.
A 6-volt negative ground is the opposite. The cars electrical system is wired with the positive side of the battery going to accessories first and the ground wire of the battery grounding to the frame and chassis of the vehicle, allowing the frame and chassis to complete the circuit. Negative ground is the norm these days. One reason is that a zap from 12 volts stings a little more than 6 volts.
Most older cars with a 6-volt system have a mechanical fuel pump, but in the case that the mechanical pump has been obsoleted or just may need a little boost. Airtex has you covered with E8902 & E8011s for 6 volt applications. These pumps are a two-wire design and are easy to install. Don’t worry if you have your wires crossed like old Ben. Airtex 6-volt pumps will work with either positive or negative ground.
When installing one of these pumps on a positive ground system, install the positive wire of the pump to the vehicles chassis (remember the body of the Airtex unit is not part of the circuit), then wire the black wire back to the negative side of the battery. On a negative ground system, the black wire is grounded to the vehicle chassis and the positive wire of the pump goes to the positive side of the battery.
Don’t forget, if you need technical assistance please call our tech line @ 1-800-484-7839