BP 101: Where does it get the engine temperature signal?

The gauge gains sensing from the wire in the Mercury harness that relates the heat buzzer. These have worked fine in repowers previously and we would check that tan with blue wire from the ignition harness we believe. It could be an issue with something in the ground often on jumping signals.

The trimgauge is because the ground must be removed from the trim sending unit and engine connection, and run directly to the terminal block. That is RF noise on the trim when the motor runs. It settles when done trimming and blacks out when trimming. It sounds like ground faults to us. Parts of older equipment is cleaning contacts.