d-120 ammeter fluctuation +- ?

Over the last few flights the ammeter on the D-120 has been fluctuating between -30 and +6. It will stabilize for a while and then do it again. The volts seem to stay around +14 while this is going on and all else seems normal. No smoke, no fire.

I checked for loose wires or connectors and checked the continuity of the wires between the d-sub and the shunt. Everything appears to be ok and I'm not sure where to look next

If anyone has some helpful advice, I'd appreciate it.

Thanks.

Might check on the alternator. The Diodes or regulator may be causing it to load and unload. Amp meter swing from +6 to 30 sounds like something fairly large.

I'd be looking for a connection issue at the shunt. Continuity checks won't help, as your problem is intermittent. You're looking for possibly corrosion or more likely a weak crimp. If your alternator current changed that much, you would be seeing a voltage drop as well, depending upon exactly where the shunt is.

Larry