Ammeter wiring

[Farm130]

How do i know that the ammeter is wired correctly. Are the posts on the ammeter labeled? And if so how are the labeled (+)(-)? On a positive ground setup which post goes to the battery/starter and which one goes to the VR (Bat)?

 

[Bob M]

Seems there's no standard for ammeter terminal designation - at least for the old stuff. Sometimes there's a red or white paint dot next to one terminal. Or you'll find "+" stamped near one terminal. But my experience is generally there's no marking whatsoever.

How to connect? Easiest way is to hook it up and try it! Then if the ammeter indicates discharge when you turn on the lights or ignition, it's wired correctly.

However if the ammeter indicates charge when you turn on the lights/ign, simply swap the wires between the two ammeter posts and you'll be set.

 

[John T]

Farm, To add just a bit to Bobs advice just in case you werent aware, theres usually ONLY ONE wire on what I call the ammeters SUPPLY terminal and thats its hot battery voltage feed usually off the battery/starter where the big ungrounded battery cable attaches to the starter switch or solenoid. Its other LOAD terminal is what wires to the BAT terminal on a Voltge Regulator or Cutout Relay PLUS feeds battery voltage to the lights n ignition. Therefore, theres often ONE wire on the Supply Side and TWO over on its other Load side, so if she registers bass ackwards do the side to side wire swap as Bob told ya.

On some of the older automotive Negative ground system ammeters the labeling convention was + = Supply terminal (to + battery post) and - = Load terminal wired to VR and switches. If such an ammeter was used on Pos ground the - goes to battery and + would feed switches and BAT on VR NO WARRANTY HOWEVER LOL Like Bob noted there may not be any labels at all???

John T