Instrument panel

[Jason]

I have a interment cluster out of a Big bump with the five gages and I was wondering if theses just plugged in to the existing wiring or if i have to modify the harness? Also do i need to change the sending units for the gages I am assuming so but would like to make sure i get it all correct.

[bluef250]

You should be able to switch harnesses between the big bump and yours. The sending units should work.

[4th effie n counting]

should be fine as long as you had gauges on your truck already.

[FORDification]

Right....if your driver has idiot lights, the amp gauge in the F600 panel won't work, but everything else will. To get the amp gauge working you'd need the engine and underdash wiring harness from a truck with gauges.

[seattle67]

Just thinking out loud here, but I'm wondering if, instead of replacing the whole engine harness, it would be possible to just install a shunt?

Like these: http://www.greegoo.com/Current-Shunt-125A.htm

[bluef250]

I think that the idiot light is needed as part of the charging system. Yes, I believe that you can also installed separate wires, one from the alternator and one from the battery side of starter solenoid, and connect to the meter. Protect the meter with 4 amp fuses like Ford did. You may also have to replace the sending unit for the oil pressure.

[seattle67]

Well, once again I find that the more I research, the more I realize I should just shut up and listen to Keith. I have been looking at the research that Keith and his father in-law already did regarding alternator idiot lights verses ammeters, http://www.fordification.com/ammeter.htm plus I have been doing a little research on my own. I was hoping I could find a simple, easy way to add a full gauge panel to a truck with a standard panel wiring harness.

My first mistake was that I was thinking of the standard shunt, ammeter configuration we commonly use on ships; they do it a little different in cars. Once I understood how Ford was doing it I turned my attention to the charging circuit.

It was bluef250 that got me looking into the charging circuits, and he is correct that on the standard gauge panel with idiot lights, the alt fail idiot light is part of the charging circuit. (though it looks like there is a 15 ohm resister in parallel with the lamp so if the lamp burns out, the charging circuit still works) Anyway, to get around this, the voltage regulator is wired differently on trucks with an ammeter. (see the following pictures)

A person could take the time to do some rewiring of the standard wiring harness, but I agree with Keith, all things considered, I think in the end it would be simpler to just swap the harness. Probably not what Jason wanted to hear.

[Jason]

My truck had the idiot lights so i need to replace the oil sending unit. My question is can Take out the idiot light circuit and rewire it for the amp meter and what will i need to do it.?

[seattle67]

Well, I believe you would have to hook up the ammeter just as blueF250 described. Also, you would need to rewire the voltage regulator from its present configuration, shown in the first drawing in the post above, to the configuration shown in the second drawing.

I have never done this modification, so I'm pretty much guessing here and could be leading you astray. Hopefully someone else out there will have some input on this.

[Jason]

Do i have to completely remove the idiot light circuit? Hooking up the Meter is not a problem I just need to know if i have to get the old light circuit out.