Odd issue with amp meter

[mkmskm]

I changed some of the wiring on my car, the harness from the cut out and starter to the terminals. The terminals to ignition/amp meter harness and the cable to the distributor. Everything is nice and tight, nice new wires, the car started right up but now at speed instead of reading 10 on my amp meter, it reads 20 Its never pegged before like that.

 

[Tom Wesenberg]

Was the old harness in really poor condition, such as serveral broken strands at the terminals? Does the new harness have solder between the wires and terminals? Some are just crimped so I'd add solder to them.

In any case I'd set the adjustable brush to a much lower output by moving it UP.

 

[mkmskm]

The old one had crimped ends, worn fabric, incorrect colors and only one had a couple of broken strands but nothing that really looked horrible. I twisted the connections of all of the old wires and they were all solidly connected to their wire. When I turn the lights on then it goes back to almost zero.

 

[johnbuckley]

My initial thought would be that you had some poor/dirty/oxidised connections on the old wiring. As Tom advises- drop the charging rate ( if the ammeter's reading is true!)

 

[BILL WILLIAMSON]

Remember, an ammeter is stupid! it has no mind of it's own & only does what it is told to do! If it gets overly hot, either its slotted nuts that secures its posts to the bus bar are loose or corroded, or the insulator between the buss bar & the case are burned & shorted. If your meter doesn't return to 0 with everything off, or battery disconnected, and you have to tap it to make it go to 0, just open the meter & oil the needle shaft pivot bearings with 3in1 oil. A quick tool to tighten the stud nuts, just use a cut off wheel to grind a deep slot in an old cheap slot screwdriver.
Remember, it is "normal" for ammeter to warm somewhat if headlights or such have been on for some length of time.
Some monhs back, Restorer magazine had a good article on restoring original ammeters. It's not "ROCKET SCIENCE!" & you can even repaint the needle while it's apart and repaint the partial black area inside for high point judging. Bill W.

 

[Richard Wilson]

It sounds like your ampmeter is working OK to me. As others have said try moving the third brush in the generator to lower the charging rate. It only takes about five minutes and is easy to do.