Any tips for getting my ammeter gauge working? The gauge has never worked since I got the truck, and I'd like to get it working again to help me diagnose the charging issues I've been having.

What is the part number for the gauge assembly?

Sam

 

IMO, those ammeter gauges don't do justice and a volt meter installed will actually give you more info than the stock ammeters. If you are looking for a new ammeter gauge assembly, you'll spend a bunch more if you find one. If you want the ammeter, I'd check out the junkyards before I spend the cash on a new one (that is if you can find one).

 

What issues are you having specifically? As buck said, the factory ammeter is just a "looks nice," it's not useful for any sort of charging system diagnosis. A voltmeter is much more useful. You can find a cheap handheld unit at most stores for under $20 that will get the job done (you can also install a voltmeter as a gauge).

 

x2 the factory gauges in these trucks seem to be designed to read halfway regardless(except the fuel gauge which is ussually empty lol) and are useless for diagnoses. i use a handheld battery/alt tester as stated above to check my charging system, much more helpfull

 

I'd like to get the stock one working, if possible. I've got a cheap volt meter I should wire up, and I've got the hand held one as well. The problem I've having is the truck isn't re-charging the battery when I drive it, or, at least it isn't charging very much. The alternator is good, the voltage regulator is brand new, and the wiring looks decent. So I'd like to get the gauge working again to tell me if it's charging or not, it could be I just not driving the truck long enough to recharge the battery. The only extra things wired in are some cab clearance lights, a spotlight, and a 12 volt outlet. I don't use the spotlight or the power outlet on the road, so the only big power draw is the headlights.

It's getting so bad I carry a second battery to swap in so I can get home!

Haha I know about those gas gauges, and it's gotten me in trouble a couple of times! The worst part is, sometimes it's accurate, sometimes not. Lately it's been telling me the most gas that's been in it, which is about half a tank. I ran out the other day, the needle was telling me half a tank the whole time. There's two gallons in it right now, and it still says half a tank. It might be time to drop the tank and clean it out!

Sam

 

If you want a NOS ammeter, here's the part number:
Ammeter, instrument cluster
Fits: 73-77 F100-350 before s/n O80,000 w/ red pointer
D3TZ-10850-A

Dennis Carpenter, Concord, NC has 6 (704) 786-8139
Wesley Obsolete Parts, Liberty, KY has 3 (606) 787-5293
Parts International, Farmers Branch, TX has 11 (972) 241-8730

There are others if you would like more dealers.
But listen to what the others are saying, these ammeters were basically useless even when they were new. It was actually so bad that Ford had to issue a technical bulletin on the problem.

 

a batt load tester can tell you that in seconds. hook it to the batt while truck is running. if alt is charging it will read 13-14 volts. if it reads 12 or less system isnt charging. if you dont have access to one , most parts houses(autozone,napa etc.) will loan you one or test it for you. really hope this helps

 

I`ve had several 70`s Ford cars and trucks, and none of them had an ammeter that moved a noticable amount. Back around 1976 or 77, I was driving home in my 1970 Mustang fastback (351C 4 barrel with Shaker scoop), after a day of racing at our local dragstrip, and apparently, during 1 of my runs, the alt belt had come off the pulleys. I drove the car home, about a 1 hour drive, and since the 351 used 1 belt that ran only the alternator, ths car didn`t overheat, or get hard to steer. I didn`t realize that I had a problem until I went to start the car the next morning, and the battery was weak. Only after I opened the hood did I notice the missing belt. The factory ammeter didn`t indicate a discharge, even with my headlights on. Subsequent vehicles and my current 74 F350 also had essentionally non functioning ammeters. All the other gauges (fuel, oil prressure, and temp) always seemed to work fine, but not the amps. By comparision, I used to own a 66 Dodge that the ammeter would practically send the needle bouncing from the speedo to the radio, when the turn signals were on! I wouldn`t spend any money on a new factory ammeter, it likely wouldn`t make a differance. I have to think that Ford must have had many complaints about these ammeters back when the vehicles were new.

 

Alright, thanks guys. I'm pretty sure it's charging, reads 14 volts at the battery when running. I'm just not sure if it's charging enough to make up for the headlights, cab/running lights and recharge the battery from the drain from the starter.

Sounds like the stock ammeter is a bit of a lost cause, anyone make a repop that looks stock and works?

Sam

 

I just noticed something, the E series vans used the same gauge cluster as our trucks up until the early 90s, were the ammeters in those rigs any good? Maybe I could pull the ammeter out of one of those and swap it into my rig.

Sam

 

Even when the ammeter gauge is functional it doesn't really "work".

Ford Ammeter Gauges: Do They Work? | MILEPOSTS Garage (Tech Tips)