Ammeter shunt

[PDG]

Picked up my plane from its annual. Did several t/gs with a CFI and everything went well. Let the instructor off and started the engine to fly home. At this point the D120 showed that the Rotax was charging at +99 amps! After several trouble shooting steps and calls to DYNON and FDUSA the decision was made to check the in-line fuses at the shunt. On examination it was found the one on the connections to the shunt had corroded and that the lead had fallen off.

 

Repairs were made to the shunt connectors and the engine was started and all was well! During the flight home observed that the ammeter dis less bouncing than was normal before this repair.

 

For anyone with very bouncy ammeter reading it would not hurt to examine the shunt connectors. The shunt is located on the cockpit side of the firewall behind the D100.