How do I test my Alternator gauge?

[1BAD351 21]

I think it might be causing me some major electrical issues. Is there any way to know if it's working properly or if it's shorted out? It's always in the middle of the gauge even with the battery off. I know it doesn't move much with the car hooked up, but does it still stay centered even when the battery is disconnected?

[dzahm 10]

1st- not sure if mine works either- but mine reads a hair on the discharge side when sitting. More towards D if you turn on lights etc. When I start it jumps to the charge side but only for 10 secs or so. Then back to slight D. Periodically when driving it will wiggle, like a heartbeat, for 10 secs or so then back to D. I think my volt reg is solid state, don't know why it wiggles, but it seems to follow how I think the charging system works.

[LiLMike 42]

Remember amp gauges are connected in line and will indicate the amperage in that line. You have 40 year old wiring that will effect the reading. If you install a high amp alt, then you are overloading the gauge and could possably burn up the old wiring. The simplest way to check an amp gauge is with the car not running and turn on the headlights. The gauge should move to the "D" side slightly and back to the middle when you turn off the lights. I have noticed over the years that amp gauges fluctuate when the car is running. Just the old technology and the nature of an amp gauge. A volt gauge measures voltage in that circuit to ground, which I like better.

[69RavenConv 286]

Fortunately, by 1969, they were using shunt type ammeters instead of the in-line versions that used to send 30-40 amps thru your dash board back in the old days. The bad news is they don't work very well.

 

One side of the gauge is a yellow wire that connects down by the alternator output. The other side is a red wire that connects by the solenoid. Two different ends of the same wire. The idea is that if the voltage is higher at the alternator, current is flowing into the battery and the needle deflects towards "charge". If the voltage is higher at the battery end, current is flowing out of the battery and the needle deflects towards "discharge". Disconnecting one or both of those wires will take the gauge completely out of the circuit.

[1BAD351 21]

I don't really care if the gauge works to be honest, I have an aftermarket one. I just want to be sure it's not causing me electrical issues. I'm frying voltage regulators in this car like it's my job. But I have a feeling it's due to my shuttle being stuck in my distribution block and in turn grounding that circuit.

[69RavenConv 286]

Removing one or both those wires will eliminate the ammeter. It's unlikely its causing your problem, since ammeters usually go open circuit when they fail, basically removing themselves from the circuit. But disconnecting it can't hurt.