amp gauge

[69RSZEE28]

How do I test the amp gauge for 69 out of the car?

[69Z28-RS]

From what's been said, it seems a very small dc voltage would engage it.   (a 1.5 vdc battery with a pot across it to allow adjusting the pot output from 0Vdc toa few millivolts?)..  (D'Arsonval movements are very sensitive to very small voltages)

[bertfam]

To test the amp gauge connect a partially dead AA battery (+ on pin 3 and - on pin 4), it should register 40 amps charge (depending on condition of battery), reverse the AA battery and it should register 40 amps discharge. I got one of these at Radio Shack for a few bucks just for this purpose (see below).

I recommend you don't use a new battery since it'll be 1.5VDC. The one I have I got out of my Cable TV remote when it wouldn't work anymore! It read just under 1 volt. Also, don't leave it attached for too long. Just long enough to see the needle deflect both ways.

Ed

[Mark]

Be carefull, full scale deflection on the gauge is about 0.5V (0.5V will make it read full scale one way or the other)  Don't try it with 1 12V source unless you like buying new things.

[69Z28-RS]

If you hook a potentiometer across a 1.5 V battery, and adjust the pot to the LOW end, you will be at 0 volts.. and the ammeter across from the low side of the battery to the mid point, then you can slowly adjust the voltage on the ammeter until you read full deflection (and you could then measure that voltage with a meter)...   and by flipping the battery leads, you can check deflection in the opposite direction.