Broken ammeter

[bayareadave]

My ammeter guage barely moves when I start the engine or when the alternator kicks in. Is it common for these guages to malfunction?

I used that 1-page color diagram (BTW:best diagram I ever saw) to connect the orange wire from the alternator regulator to one side of the ammeter. A red wire goes from the other ammeter terminal to the ignition "batt" switch.

Is there anything that might be wrong / any way to test the ammeter? (I don't think my circuit tester has an amps function).

[Don Moyer]

Dave,

It does appear that your ammeter is not working. You can confirm the operation of your alternator by measuring the DC voltage virtually anywhere in the system, but right at the batteries would be best in a troubleshooting situation. If you have an original 35 amp Motorola, the voltage should be approximately 13.2 to 13.5 volts and if it is a more recent aftermarket model, the voltage should be approximately 14.2 volts.

If you return to your boat after a week or so (with average batteries), the amperage should be close to 15 amps or even 20 amps, dropping down to 5 or so after 10 to 15 minutes.

Don