View Full Version : TR2/3/3A TR3 Amp Gauge to Volt Meter

05-29-2007, 11:38 AM
I would really like to have a volt gauge since the amp gauge no longer works with the alternator.

I am wondering if someone could take a old amp gauge and refit it with the workings of a voltmeter. Paint the face to match the looks of the standard TR3 instruments..

Wouldn't that be nice, a volt meter that matches the rest of the instruments..

Anyone I should call to see if the could do it?


05-29-2007, 12:17 PM
what happened to your amp gauge? When I took mine apart I noticed that part had to be resoldered, and it works fine with a new 55 amp alt. if the gauge goes full scale I read somewhere you can add a shunt to one side and I it cuts the value in half I think this is right but I am no electrical person

05-29-2007, 12:45 PM
I did my wiring according to VTR and the amp meter only shows the load...

This is a quote from their instructions.. I used #8 wire and went from the alternator to the starter selenoid... Light works fine as I found out this weekend...

"The charge indicating light will work as before, but the ammeter will only read discharge. It will register the current being drawn by the various loads on the car, but will not indicate if the alternator is charging. "

I think I like the you wired it better... But I would be happier with a volt meter and you would always be in touch with the battery...

05-29-2007, 12:45 PM
If you do this, you have to connect the voltmeter in parallel with the electrical system. Otherwise, nothing electrical will work. The ammeter is in series with the rest of the system.

Connect both of the ammeter wires to one post of the voltmeter. Connect a wire from the other post to ground.

05-29-2007, 12:51 PM
But I would be happier with a volt meter and you would always be in touch with the battery...

One thing I like about our old LBCs is the amp meter. I find that keeps me in touch with the battry more the the volt meter in the modern cars. But, that is just my opinion.

05-29-2007, 01:58 PM
After switching to an alternator in my TR3 I used a voltmeter from a TR6 with curved lens glass from the TR3 ammeter.

05-29-2007, 03:00 PM
Thats a GREAT idea!!! I'll remember that...

05-29-2007, 03:09 PM
I like that also... I'm going to really look into this..

Marvin Gruber
05-29-2007, 03:19 PM

I can probably fix you up with TR6 voltmeter with TR3 Bezel and curved glass. PM me if interested.