The Ford Barn

1929 essex · 03-29-2016, 07:38 PM

I'm putting in a new dash wiring harness and I want to make sure I have the wires right. Is the charge side of the ampmeter the positive side?

DougVieyra · 03-29-2016, 07:42 PM

I am not sure. It changed at least once. Did you look in your Les Andrews MECHANICS HANDBOOK ? You will find the most recent answer there for sure.

If you do not have a MODEL A MECHANICS HANDBOOK by Les Andrews, you really do need to get one. It will save you hours of frustration and a great many mistakes.

1929 essex · 03-29-2016, 07:52 PM

I looked in the mechanics book and the charge side is the positive side. Thank You for reminding me about the book.

Tom Wesenberg · 03-29-2016, 07:58 PM

I would connect the two wires, turn on the lights and look for the needle to move to the discharge side.
If it move to the charge side, then swap the wires.

Mike V. Florida · 03-29-2016, 10:20 PM

Quote:

Originally Posted by Tom Wesenberg

I would connect the two wires, turn on the lights and look for the needle to move to the discharge side.
If it move to the charge side, then swap the wires.

Without knowing where/when you bought the meter follow Toms advice. Some of the Model T amp meters look like the A meter but works with neg ground.

1929 essex · 08-19-2016, 03:52 PM

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Before I took the old harness out I wrote down the connections and it was wired backwards so when I put in the new harness I wired it the right way. That's when I saw that it showed discharge, I followed the advice of the replys and my lights showed charge when not running. I now have the wires switched and it shows discharge when my lights are on but not running maybe I do have a Model T ammeter. Does anyone have a good picture of a correct ammeter?

coupe1942 · 08-19-2016, 04:14 PM

Here are some totally random photos I have of my original and the replacement. Hope they help, but not the best photos. I have no idea if they are the correct ones or not, other than the repop one was made in Taiwan. My truck has a 12v system with negative ground it is running.

Good luck on your fix.

BILL WILLIAMSON · 08-20-2016, 09:13 AM

Ammeters can be a pain in the neck, sometimes. Make sure the slotted nut that holds the posts to the case are TIGHT. Especially if your ammeter gets HOT! The ammeter is SIMPLE, just 2 posts & a brass bar & a little thingy that makes the needle move, through induction.
Bill W.

Ruth · 08-20-2016, 09:35 AM

Quote:

Originally Posted by Tom Wesenberg

I would connect the two wires...

If you connect the two wires, how is going to read your amperage??

Kidding.

100IH · 08-20-2016, 02:09 PM

Tom means, connect the two wires to the meter and then see what the meter shows with a load (like the headlamps).

03-29-2016, 07:38 PM	#1
1929 essex Junior Member Join Date: Feb 2016 Location: Green Bay Wi Posts: 24	ampmeter I'm putting in a new dash wiring harness and I want to make sure I have the wires right. Is the charge side of the ampmeter the positive side?

03-29-2016, 07:42 PM	#2
DougVieyra Senior Member Join Date: Sep 2012 Location: Eureka, California Posts: 1,716	Re: ampmeter I am not sure. It changed at least once. Did you look in your Les Andrews MECHANICS HANDBOOK ? You will find the most recent answer there for sure. If you do not have a MODEL A MECHANICS HANDBOOK by Les Andrews, you really do need to get one. It will save you hours of frustration and a great many mistakes.

03-29-2016, 07:52 PM	#3
1929 essex Junior Member Join Date: Feb 2016 Location: Green Bay Wi Posts: 24	Re: ampmeter I looked in the mechanics book and the charge side is the positive side. Thank You for reminding me about the book.

03-29-2016, 07:58 PM	#4
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: ampmeter I would connect the two wires, turn on the lights and look for the needle to move to the discharge side. If it move to the charge side, then swap the wires.

08-19-2016, 03:52 PM	#6
1929 essex Junior Member Join Date: Feb 2016 Location: Green Bay Wi Posts: 24	Re: ammeter Sponsored Links (Register now to hide all advertisements) Before I took the old harness out I wrote down the connections and it was wired backwards so when I put in the new harness I wired it the right way. That's when I saw that it showed discharge, I followed the advice of the replys and my lights showed charge when not running. I now have the wires switched and it shows discharge when my lights are on but not running maybe I do have a Model T ammeter. Does anyone have a good picture of a correct ammeter?

08-20-2016, 09:13 AM	#8
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: ampmeter Ammeters can be a pain in the neck, sometimes. Make sure the slotted nut that holds the posts to the case are TIGHT. Especially if your ammeter gets HOT! The ammeter is SIMPLE, just 2 posts & a brass bar & a little thingy that makes the needle move, through induction. Bill W. __________________ "THE ASSISTANT GURU OF STUFF" Last edited by BILL WILLIAMSON; 08-20-2016 at 10:52 AM.

08-20-2016, 02:09 PM	#10
100IH Senior Member Join Date: Dec 2011 Location: SW Idaho Posts: 970	Re: ampmeter Tom means, connect the two wires to the meter and then see what the meter shows with a load (like the headlamps).