low voltage

[tobo57]

On my 03,21i with 350mpi, 315hp I'm not getting a good solid 12 volts to my ignition. Can someone tell where the hot wire comes from or what may be the problem. Volt meter on dash jumps all around. Even though connection on rear of alternator is on tight.
Thanks,
Joe

[Tip]

Joe,
This sounds very similar to the problem I was having. The volt meter would jump all over the place, and usually only indicated around 10-11 volts. The funny thing was that the batteries always stayed charged. The problem ended up being the wiring harness plug that connects to the engine. The pins in the plug are the split type, I took a knife and carefully spread the pins (approx 1/32 or an inch) then reconnected the plug and the volt meter now reads a steady 13 volts.

If you look at your engine manual there is a wiring diagram that shows which wires are which.

Good Luck,

Tip

[tobo57]

Thanks for the advice,I'll give it a try.That sounds just like the problem I am having.

[tobo57]

Thanks Tip,
That was my problem.Perfect Pass would not go on at times,temp. guage read high at times and volt guage read low and would flucktuate.Now all work well.
Joe