Posted by David Sherman on October 26, 1999 at 20:58:30:
In Reply to: How to wire gauges???? posted by David Hogan on October 26, 1999 at 10:06:31:
Ammeters are usually marked, but it's easy to check: just wire
it up and see if the needle goes the way it should when you turn
on the headlights. If it goes the wrong way, swap the wires. No harm
will be done by hooking it up backwards.
The fuel gage doesn't care about positive or negative. One wire goes
to the battery/ignition circuit (supply), one goes to the fuel
sender, and if there's a third wire it goes to ground, otherwise
it's grounded through the case. It doesn't matter if it's a positive
or negative ground truck.
Ammeters don't care about the voltage of the system, but fuel gages do
and they also have to match the sender.