[Carbine kid]

Is there a repair for the ammeter or just replacement in the 18 years I've owned my mustang I don't believe I've ever seen it move even after my recent voltage regulator issue that was overcharging the battery.
Thanks in advance.

 

[Charles Reeves]

If you've checked the wiring, etc. and are sure it's getting current, I'd just replace it. Doubt it can be repaired. Here's one, although a little pricey (and I have no connection to these folks other than being a satisfied customer):

Mustangs Unlimited - The Premier Source for Mustang, Shelby and Cougar Parts and Accessories

I replaced mine years ago, but don't recall what I replaced it with. Don't believe it was stock, since I had to use a resistor to get it to read on-scale.

 

[David Suesz]

There is usually nothing wrong with this gauge. The problem is the parallel wiring is uses to sense charge/discharge. The slightest bit of corrosion on any plug pin between the gauge and alternator will prevent indication. Pull all the plugs apart, one by one, and clean them with cotton swabs and a toothbrush, using Brasso. Put a little silicone grease on them when plugging back in. Most likely, you'll see plenty of movement then.

 

[gizmo.7000]

In addition to what David has said, you can use a multi-meter to test the windings inside the gauge.

Pull out your instrument cluster and set the multimeter to the Ohms scale.

Place the probes across the connectors of the Ammeter. If you get a reading it means the gauge is good and the windings are intact.

If you get no reading it means the gauge is toast and will need to be replaced.

 

[rex1965]

These vintage ammeters didn't move much, when they were new, a 20A draw would barely make the needle move, if you were watching. My 2 cts. Good Luck.

 

[6T6Coupe]

Mine never moves...always right in the middle. Even with heater, headlights and all on. idk if its broke or what. I also replaced alternator & Voltage Reg. not long ago. still no movement in gauge. :yup:

 

[Ivy66GT]

That is about the price of a new one from anywhere. Never seen one so can't say how well they work.

As already suggested, there is likely nothing wrong with yours. The connections may need cleaning as David mentioned. Otherwise, they never did work very well.

http://www.allfordmustangs.com/forums/classic-tech/233652-1966-mustang-ammeter-wiring.html

 

[Carbine kid]

Thanks all I'll ohm it out first than clean everything up at least I won't be wasting money on a new on if its good.

 

[Charles Reeves]

These vintage ammeters didn't move much, when they were new, a 20A draw would barely make the needle move, if you were watching. My 2 cts. Good Luck.

Maybe that's why I replaced mine years ago, as mentioned in my previous post. With my setup it starts about halfway to the right after the car starts, then slowly comes back to the center. This is how I think it should work.

 

[Ivy66GT]

From what owners report I have a feeling that the new ones deflect more than the original ones but I have no real data to prove that. And, yes, that is how it SHOULD work but the original ones didn't. With the car running I have never seen either one of my original ones deflect more than the width of the needle either direction. You have to watch really close to see that small of a movement.

They looked really nice in the showroom. :gringreen

Pulling the wires off at the solenoid and playing around there I can make the needle move as much as I want but that doesn't happen once its plugged back into the harness. They probably eliminated any warranty claims for the charging system since the ammeter NEVER indicated a discharge.

 

[snaranjo]

Think I read in Mustang Monthly a while back that most original ammeters in our classics have given up the ghost. Mine has been planted dead center since about 1975:gringreen