Need help again
which wire goes to the voltage gauge, I'm guessing is one going to alternator but dont which one it is.
thanks

 

Probably more like one of the wires to the voltage regulator, than the alternator.

You could tap into an accessory wire under the dash. You want something like the power lead to the radio, so that the gauge doesn't stay live when the truck is off, and drain the battery.

 

Just to be sure, you're talking about the factory ammeter (amp gauge)? Or are you installing an aftermarket volt-meter?

Paul

 

Whatever you are doing I sincerely hope you are not trying to install an aftermarket ammeter and it's in fact a voltmeter you are looking to install.

 

I'm looking for the wire that works the factory guage. My bad I'm used to the volt guages on other cars.

 

no I changed the engine and a different alternator
and dont know if anything from the old wires connect to the new engines alternator

 

Unless it's one of those cool Dakota Digital ones. They've got some that use a remotely mounted inductive loop that fits around the charge wire and sends a digital signal to the in-cab gauge.
Pretty cool I think. Even if it's just used as a diagnostic tool.

Paul

 

What did you change to? I'm "assuming" that you're now using an internally regulated model, such as a Ford 3G or perhaps even a GM-based 1-wire swap?
If so what did you do with the old voltage regulator wires? If repurposing them to run the new (internal) regulator, then maybe the gauge will still work.
Of course, that's assuming it even worked before! Which most don't.

I'd guess it's possible to keep it working, and that someone here with more electric theory knowledge could figure it out. But pretty sure that most just add a volt-meter and call it a day. Most of them may already have a volt-meter anyway, since the original ammeters were so finicky and failure prone to begin with. Very funky design maybe, but part of the issues could also stem from the P.C. board's old age issues as well.
Depending on the vehicle and how determined you are, instead of just a separate add-on meter you could replace the original gauge with an original one from a later Ford truck. By "later" I mean after they dumped the ammeter and went to volt-meters in the dash.
Maybe by now there's a kit for that?

That's what we do in the original Early Bronco gauge clusters, and I think I remember a discussion here about doing that in our '73-'79 clusters. But I don't remember the details of what gauges were used, or how hard the swap was. Or even if it looked original enough to be acceptable.
Hopefully someone will know some simple way to connect the old wires (that were connected to the regulator by the way) to get the old gauge to work.
But it looks to me that if you find the wire where it's spliced into the Yellow wire from the old regulator, your ammeter would still have it's signal.

One part of the loop is spliced into the Yellow regulator wire, and the other half of the loop is spliced to the Black w/yellow power wire to the cabin and fuse panel.

Paul

 

Yes I changed to a gm single wire alternator.
the original amp guage was working when I pulled the old motor. Not sure what all I have to do with the old regulator wires, do I even need them for anything I have power to the starter solenoid and most everything seems to have power. Have not finished everything I'm doing yet but from what I've checked everything has power

 

The factory ammeter works off a shunt wire, once you do a alternator swap it will not work again.

 

You do not need any of the functions of the old voltage regulator, because the new alternator has one mounted inside the alternator case.

390gashog, if you left the old regulator connected to the harness (but obviously not doing anything anymore) would the ammeter still receive some kind of signal?
The only wire that would no longer be connected to anything would be the Orange field wire, but the rest would still be sampling system voltage (Yellow) and simply switching on and off with the key (Green w/red) but not doing anything.

Does lacking the Field function negate the ammeter shunt's ability to operate the meter?
Mine almost never worked anyway, and my new Dakota Digital cluster makes all that moot for me, but curious if there is a way to keep the ammeter working with an internally regulated alternator.

Thanks

Paul

 

The reason I said it won't work is because you should not be using the stock charge wire. With alternator upgrades you need to remove the stock charge wire and replace it with a wire sized for the upgrade. With a 130amp 3g alternator you need a 4ga charge wire and a 150amp mega fuse. The factory wire is barely able to handle 60 amps and has a fusible link.

 

Correct with the bigger charge wire for the big alternators. But I think I gotcha now with the shunt wires.
I was probably reading diagram wrong, and have always thought the sensing/shunt wires were among the smaller regulator wires. Not spliced into the main charge wire (which would actually make more sense anyway) and have never actually seen the splices.
I also do not remember seeing a connection when I removed the charge wire from the alternator and replaced it with a larger gauge wire.
If it's where the large Black wire runs between the alternator and the starter relay, then yeah, you're stuck without any way for the meter to get it's signal.

Thanks

Paul

 

Since you replaced the shunt, the ammeter will no longer work but all is not lost. You can have your ammeter converted to a voltmeter by Rocketman's Classic Cougar Innovations. You send him your old gauge, he reworks it into a factoryish looking voltmeter for about $40. I think it's a 1 man shop so he may not be fast but I've heard good things about the gauges he's done.

Michael