Wiring Harness

[rfariss]

I am replacing the original dash display with Auto Meter gauges (71 XLT). My issue is this: From the wiring harness to the Amp gauge is a red and a yellow wire - (two separate wires). On the new gauge there is power (+) connector and a ground (-) connector. I'm not sure how to wire the new gauge utilizing the original harness. Can anyone shed some light?

[Dragon]

you can't use the original wires they will fry the harness. The instructions call for 10 gauge wires

[rfariss]

Dragon,
I'm not sure I understand - sometimes you have to draw me a picture. The original wiring harness to the dash panel/gauges is what I'm trying to use and there are two wires from the harness to the original alternator/amp gauge - one is red and the other is yellow. The Auto Meter amp/alternator gauge has two connectors - one for power and one for ground. Is the red wire to be connected to the power (+) on the Auto Meter gauge and the yellow to the ground (-)?

[Dragon]

Right and if you use those original wires you will burn them up. They are wire # 654 and 655. Our old ammeter did not measure current like the new gauge. It had tiny wires and only really measured a part of the current, like 2 amps for a 10 amp swing. That is why they move so little. Your new meter will read from 60 Amps and probably allow 30 amps through the wires. Sending 30 amps through the 16 gauge #654 and 655 wires will fry them and when they melt they will take out your dash wiring harness all the way across the back of the dash to the passenger side then out and forward to where your wires make contact under the hood. You will have to repair or replace a good junk of that wiring harness.

Originally the factory wiring had 2 fuses one on each leg and the fuses were 4 amps. You also need fuses 60A types one on each leg of the ammeter wiring. If you take 60 amps and feed it through a welding rod you can melt the body sheet metal.

[rfariss]

Thanks. That's the "picture" I needed.

[Dragon]

No Problem

[Thunderfoot]

On the new gauge there is power (+) connector and a ground (-) connector.

This is not right for an "Amp Gauge" are you sure it is not a "Voltage Gauge" you have?

[Dragon]

You know when I looked at the Autometer gauges site all their meters had S and I terminals.

[rfariss]

I'll check those items, Dragon and Thunderfoot, and get back to you tomorrow - I'm not at the garage currently.

[fordman]

if the gauge came with instructions i would use those instructions. but running new larger wires do sound like a good idea to me.

[Dragon]

Autometer only makes 3 ammeters and all 3 say use 10 awg wire.

[rfariss]

It is a volt meter - 8 to 18 volts. Given this, I should be able to use the original harness, correct? If so, which of the wires (red or yellow) ties to the positive terminal on the gauge and which ties to the negative terminal. According to the directions if I were using an ammeter I would have to use the heavier wire.

[fordman]

http://www.fordification.com/tech/wirin ... master.jpg

[rfariss]

Thanks, Fordman!

[Dragon]

It does not matter which color goes where as long as one is on bat + and the other is on ground. The wires built in will work fine. Since in DC systems Red is usually positive I would go with that.