How to test the Ahmeter / fuel gauge with a 9volt battery at home

[jalexquijano]

I have fixed and tested the clock in my 240z with a 9 volt battery and some alligator clips. Everything Works fine but i am still thinking on sending it to Ron for a quartz movement upgrade.

How do i test and verify the ahmeter/ fuel gauge and the Temperature / oil gauge with a 9 volt battery after opening it and cleaning the inside? I just want to be sure before i install them in the car.

Anyone???

[SteveJ]

I don't think the 9V battery will have enough energy to drive the ammeter enough to tell you anything useful. Also, if you wire it wrong, you could damage the meter.

For the fuel gauge, you would hook up the positive of the battery to the positive side of the gauge. From the gauge, one wire would go to the negative side of the battery, and another wire would go from the sender side of the gauge to a potentiometer and on to the negative of the battery. You would vary the resistance to see if the needle deflects. As for the value of the potentiometer, you would have to search through the FSM to see the resistance range for the sending unit in the fuel tank.