Detail on how to make a repro ammeter look like an original Model A ammeter.
 

In a previous post, I mentioned how you could modify a repro ammeter and make it look more like an original. That created a LOT of emails and PMs! Glad to help out whenever possible. Since 99% of you know way more about cars than me, on the rare occasion that I can help someone else, it's great.

Discussion of that post caused a friend to ask me to do an ammeter for his Model A. Decided this would be a good opportunity to share the process in some more detail and give a better idea what is required to make a more original looking, and accurate ammeter for your Model A.

Picture 1 shows a new reproduction ammeter from one of the popular parts suppliers, right out of the box. Not bad, but could be better. Also, the accuracy of readings isn't perfect right out of the box. The worst part is, the connections inside are not electrical connections, but just mechanical connections which seldom are perfect. Worst of all, the internal connections can become resistive over time as the metals react with each other, vibration, and simple oxidation. This will lead to failure of the ammeter, electrical problems, or even burnt wiring or a fire.

The first thing you need to do is disassemble the ammeter. A small screwdriver and some patience will pry it apart. Be very careful to not bend the soft outer chrome ring. Gentle prying while turning the ammeter around will slowly separate the pieces. The top of the can has a bump that fits into a recess in the outer ring.

Once open, you have full access to the innards, including the connection between the plate and studs inside. If you use a small file, you can scratch the metal (was brass in this example) around the heads of the threaded studs and the strap inside. Then, using a high wattage soldering iron or gun and some paste flux, solder the connections together as shown in Picture 3 (sorry for the blurry pictures, they are typical cellphone camera quality). Picture 2 shows the resistance through the ammeter before soldering the connections. Picture 3 shows the resistance after soldering. Went from 0.3 ohms to 0.0 ohms.

Next step is to paint the inside of the ammeter so you don't see the brass in the background behind the meter (and it makes them look more original). Clean the inside of the ammeter with lacquer thinner on a wood handle Q-tip and then let it dry for a couple hours. Next, mask off the outside of the meter and the lower mechanical part (if you get paint in here, the meter won't move freely anymore). I like to use a semi-gloss black lacquer because it looks closest to an original ammeter when done. Use whatever makes you happy. After the paint in the background is dry, I remove the mask tape over the needle and strip the white paint off to get it down to bare silver metal. Then, I shoot clear over it so it stays bare metal looking (my original ammeter had a bare metal meter, so that's how I do the repros). You can leave the needle painted white if you prefer. Let all the paint dry for at least 24 hours in a warm, dry area.

Once the electrical connections are solid and the paint is completely dry, next step is to calibrate and zero the meter. This takes some time to do, but worth it if you like to know what is really going on. The zero and calibration adjustments interact, so it's best to "creep up" on the calibration in small increments. Picture 5 shows adjusting the small tabs to zero the meter. Picture 6 shows the calibration tabs to bend up or down. I use a fixed load (parallel light bulbs) and power from a variable voltage bench supply to calibrate. Use an inline digital amp meter for comparison. The Model A ammeter and the digital meter should be in series. I like to calibrate with a 20 amp load because it's about the most you'll ever see on a typical car with halogen lights. Calibration must be performed with the front plate sitting in place (not the whole glass and metal ring though) because the aluminum faceplate can affect the calibration on some ammeters.

Picture 6 shows the completed product. Looks just like the original, except reads 30-0-30 instead of only 20 amps, and it is calibrated and accurate within +/- 10%, unlike the originals!

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Thanks very informative

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Great idea on how to improve a repro part, thanks for your time on this.

-DAN

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Any suggestions about which supplier currently has the best replacement ammeter? My car has an older repro ammeter that is really poor in terms of appearance and calibration and I need to upgrade. I havent found a suitable original either. I wonder if the innards of a rusty original could be transplanted into a repro case?

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

You are obviously a master at this procedure. Thanks for shareing.
Al

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Isn't it amazing what a difference small detailing does to a car. Even using a weak car wash mixture, small brushes & wipe with a towel in all the tiny areas. Under the car, I mist it with spray "GOO OFF" or "GOO GONE" then wipe it with a slightly damp towel, then with a dry towel.
Look at attached pic of a beautiful OCPU for sale, dirty motor, 20 minutes of wiping & it would have been almost a showpiece. The rest of the truck was immaculate! Bill W.
(Tip # 217----Pat left behind about 30 miscellaneous make up & other brushes that I can't identify??? Saved them for cleaning, woodgraining, etc.) One make up brush looks almost like the window shade pull down on a Town Car?? I installed it on my like new back shade in the coupe! I have a shifter knob that used to have a clock, I'll fit one of Pat's cheap quartz watches in it!

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

billy bob,
were talkin ammeters here
maybe you can start a new thread on washing and cleaning the model A
the dog must be drunk
lol

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

You know, when you have guys sitting at the bar, then at the end of the bar it makes a turn to the side, and there sets Norm.:D

Norm and Cliff are always sitting at the side bar.:p

Is this an NOS ammeter or is it just an aged repro?
 

I was recently offered an ammeter new in a box, per the attached two photos.

Is this NOS, NORS, REPRO, what?

The owner claims that it is an original NOS Ford ammeter for a Model A Ford.

Thanks for any insight.

Fordially,
Brad in Maryland

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

That is NORS but maybe better than the new reproductions. I have one in my car

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Who in the world would give this helpful, informative thread a one-star rating? Reveal yourself one-star bandit!

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

I was wondering also, if anyone sells a decent ammeter today? This thread is four years old is there a good one on the market now?

Or, who sells a good reconditioned original? Mine is a 70's- make ammeter and it's doing some bizarre things lately. The Pos. post on the ammeter is loose. I went to clean the connections today and the knurled plastic nut is frozen on there pretty tight. Can't budge it maybe it got hot. Soaking it in WD-40 this afternoon. Think I'm going to be needing a new one here soon. Thanks.

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

It's good to know how to properly calibrate the ammeter. Most of us have probably never done more than rotating the gauge plate to get the needle centered on "0".

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

I had a nut that was stuck, I soaked it several days but it would not come off. I put some muscle on it and the whole bolt started turning in the ammeter, I needed some way to hold the bolt from turning so I could get the nut off. I glued a bolt to the head of the terminal bolt with J B Weld to hold it, and I was able to get the nut off. The bolts snapped apart easy after I got them out of the ammeter. I scraped the J B Weld off the head, then cleaned and painted everything and put it back together.

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Very possibly. I was on a tour in Florida a month or so ago and spoke with a supplier that said he had one in the works. His fear was the price would be too great, but he said it would be the last one anyone would ever need to buy. My guess is it will be in the $75-100 range. To some that will likely be a value, ...and to most, probably not.

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

If it passes fine point with no deductions it would be worth that price.

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Agreed with Mike V.

Re: Detail on how to make a repro ammeter look like an original Model A ammeter.
 

Not seeing whare you solder the wires, too blurry in photo.