All,

I was attempting to swap the old ammeter out and the new one won't let the truck start. The old gauge has a + and - terminal and if disconnected won't allow the truck to turn over. The new one has an I and G terminal and won't let the truck turn over despite showing 12v when the key is turned to the on position.

Thoughts?

Old on left new on right.

 

Aftermarket, no one can possibly know what went wrong. Best to not try to run all power through a gauge. Follow wires back to source and reconnect original wires and get a switched power volt meter. JMO

 

Oh I wish it was that simple.

 

Oops. Wrong discussion, wrong forum.

 

Who's left?

Ammeters don't reflect volts negative or volts positive, they measure amps drawn through them.

How are you wiring it, what do the wires go to?

 

Well, that’s interesting. I wonder whose thread got my nice comments about ammeters?

sorry about the confusion guys. Confusion in my head anyway…

 

As was said, that is an aftermarket gauge, so we don’t really have any idea how it was connected.
It also sounds like you’re replacing an ammeter with a voltmeter. As was said, also, they don’t measure the same thing. Just for clarity, can we see the gauge faces as well?
One is usually not connected the same as the other, so you can’t really use the same wires for each. Usually…

What color wire is connected to each post? Please post a picture, or pictures of both wires.

Does your truck have the factory amp gauge? Or is it equipped with a warning lamp instead?
They obviously didn’t use the original wires for a 73 to 79, because they are simple shunt wires, and there would normally be no way for those wires to keep your truck from cranking or starting.

 

Reads to me like you are trying to replace an ammeter with a volt meter. If a volt meter, "I" is to ignition or accessory ... and "G" is to ground.

I did not mention relays earlier, but it's what I use. I trigger a relay with accessory power, then the relay feeds battery power from a 5 amp fused feed to the "I" of my volt meter.

I have occasionally wired the volt meter "I" straight to the battery "+" terminal, on a 5 amp fused wire, and placed a toggle on-off switch on the ground or "G" side, but one must remember to turn it off if parked or it will run a battery down in time.

 

Sent mine to Rocketman amp meter to volt meter,,,,quick turnaround

 

I 've been out of town for work and put this on the back burner but I may have figured it out while away. The old gauge is an Ammeter. The new gauge is a volt meter. The kit LMC sells comes with a voltmeter. Does anyone know the name of the company that makes the gauges they sell on LMC so I can get the matching ammeter gauge?

 

It's kind of proven that you don't want an ammeter. All vehicle power has to pass through it, both battery and alternator. If you plan on going higher amp and direct to battery it renders the ammeter pretty much worthless anyway. Each to his own though.

 

Agreed for sure.
I’m a big fan of ammeters, but only of the type that Ford used in the early bronco. It used an inductive loop and no direct connection to the battery charge cable.
Power simply passed through the wire in both directions and the ammeter read it indirectly.
The next generation of that was for Ford to use the shunted meter that your truck had originally.
Where the power went directly to the battery from the alternator, but a couple of small wires sampled that in millivolts or something like that, and the gauge read off of that.
So you never had full power going through the instruments.

Anything in the aftermarket, except for an inductive reading, remote ammeter from Dakota Digital, is going to be a dangerous way to run your gauge and check the battery.
Best to stay with a voltmeter and connect it correctly so that you have power to the vehicle.
As I think we probably said earlier, or at least, should have, if disconnecting the gauge kills power to any part of the vehicle, it was connected incorrectly and you don’t want to be using it that way.

you have some wire figuring yet to do.

 

Well I may need help in deleting it and rewiring. Between what the previous owner did and the dealership back in the 70s a lot of the wiring is OFF the charts.

Anyone familiar with the Explorer/ Camper special dual battery with camper, trailer, aftermarket gauges package?

 

New one on me. Never heard of it before.
I know Ford offered the Explorer, the camper special (and variants) and a dual battery option.
Didn’t know they offered aftermarket gauges.

 

As far as I have been able to tell just about everything here wired up off the charts was either done at the factory or dealership. Through some readings I was able to figure some of this out and found some internet drawn schematics that are close to what I have.

I think I figured out a way to delete the ammeter safely. Will try and wire in volt meter another day when I get the other gremlins killed.

My white black off the the stator terminal I think I figured out yesterday is looping back on itself, it hits a factory looking plug that Ts into a blue wire, one end of the blue wire ran straight to the fuse panel and the other end ran back to the trigger on the auxilary solenoid with a 7.5 glass fuse in it I think. I'm guessing this is some kind of voltage sensing circuit for a reference? Couldn't find any talk of this in any of the forums or diagrams. All diagrams show S terminal wht/blk either being used for regulator or electric choke. Truck came with manual choke. Regulator is setup up for "With Gauges" option but had some extra odds and ends that didn't look like it could have been setup by your average home mechanic. Found the YLW/BLK cable chopped and hidden in the harness near the alt, traced that back to the circuit board plug but not sure of function, same with a RED/YLW wire that goes back to the board also not sure of function. I can trace the YLW/BLK and RED/YLW on the diagram from the board where they join up with other branch circuits but can't really tell what their purpose is.