I have a 57 Ford F100 with a heavy duty truck instrument cluster. The ALT gauge has a loop on the back of it. Can anyone tell me how to properly wire this gauge. I know the wire runs through the loop. Does it start from the battery post on the starter relay and end on the battery post on the ignition switch?

 

Bump to the top.........anyone have a reply?

 

starter relay - thru amp guage - terminal B on light switch.
at least that is what a '56 wiring diagram shows on an old thread on FTE.

 

It has to be wired so that the battery hot wire is on one end of the wire going thru the loop, and the output from the alternator is on the other. So it depends how you did your alternator.

I have to say, an ammeter is about useless with a good alternator, within a minute after a hard cold start, it will be reading zero for the rest of the trip. A voltmeter would be more useful, and I hate to say it, but so would an idiot light.

 

I think Badgerhound posted some wiring diagram pics a few weeks ago...his were for an older truck, but the wiring concept is the same. I agree with Albuq...a voltmeter is more useful and in my opinion safer to wire in...you don't need to route the heavy current charging wires into the panel, so all of the heavy wires can stay under the hood.

That being said, it might be hard to find a voltmeter gauge that will fit into the cluster.

Dan

 

Updating to a new volt gauge would be the correct thing to do if I were going for the new old school look. I want to keep as many of the original manufacturer features as possible. That's what gives my truck its distinguished character. I got the wiring diagrams, they provided the details I was looking for. To understand how something is supposed to work opens the door to future posibilities. Thanks one and all for your suggestions.