Have a repro improved ammeter. Wondering, if facing the back of the ammeter, which terminal, left or right, should be the one connected to the switch battery terminal? Charts say the left, but apparently these are all wired backwards? It's a 20-0-20.
Yes, I know these are trash repros but I just need something temporarily while I get my T up and running.
Hook it to the two yellow wires.
Turn on the lights, if it shows discharge, you got it right.
If it shows charge, reverse those two wires.
What James said.
John, I suspect the improved ammeters available today use the internals from the Model A ammeter. Since Model As are positive ground, we have to wire our ammeters backwards on our negative ground Ts for them to read correctly.
Thanks James! Still have to get the wiring installed but I'll do that when it is.
Tim, which one is the right one in the first place for Ts? The left (facing the back)?
This is factory color wires, if the meter reads charge when you turn on the headlamps, with the engine not running, then reverse the two wires to the meter.
Thanks Dan, just what I was looking for.
Then which one should feed the dash light? Do you move that one also?
If you’re powering the dash light off one of the ammeter posts, yes.
Oh and John it shouldn’t actually matter which of those posts you really hook your dash light to, it’s just that one will show draw on the ammeter when the light is on and the other won’t. On my car I hooked the dash light to the tail light circuit so I would be less likely to kill the battery if I left it on.
Actually to be totally accurate you should NEVER connect anything to the solid yellow wire side of the ammeter nor to any other place where the heavy solid yellow wire is showing since that is then connecting directly to the battery post and any current draw through that connection will show up as charge current when the generator kicks in since the current will be going backwards through the meter as does all charging current. The yellow/black wire is the circuit that you should connect accessory items to like lights and such. Then when that item is turned on the ammeter will show a discharge. There are 3 of the yellow/black wires in the harness and connecting any accessory needing battery connection should tie into either end of any of those 3 yellow/blk wires.
John, would that include the horn and brake lights? Assuming it does.
I would like to add that this sort of informative and helpful thread is one of the best things about this forum. No smart aleck responses, no criticism or negativity. I happen to be completely rewiring my '23 right now and I am grateful for the expertise you guys are willing to share. Thanks!!!
Grateful as well!
Three John's in one post