Sun Temp Gauge Technical Help

[napa68]

Looking for a bit of troubleshooting guidance on my Sun blueline temp gauge.

Took the car apart in fall for an engine freshening. Gauge worked good then (reasonably accurate) with what I felt was an original sending unit.

Fast forward to this week. I get the car running, but the gauge is DOA. I have power going to the gauge, and the wire running from the gauge to the sender has continuity with no resistance of sort.

In short, are the gauges that fickle? I noticed the engine builder coated the sender in teflon paste. The sender measures about 13 ohms from base to terminal at room temp (63 degrees).

Thanks,
Tim