The Saga Continues... Temp Gauge

[Paradise Ridge]

Howdy All,

Temp gauge/sending unit issues.

So I’ve got two temp gauges, tester light and jumper wires.

With either gauge in the dash, if I ground the green wire where it attaches to the temp sending unit, the gauges peg. If I jumper the 3 O’clock clip in the dash (hot) to the gauge and ground the 9 O’clock pin on the gauge, the gauge pegs.

Logic tells me to check the sending unit, so I get the engine nice and toasty and connect the tester to a good power source and check the unit. Nuthin’ at the clip the green lead hooks to, but plenty on the sending unit body where it screws into the engine block.

So I assume it’s the sending unit, right? I just bought the darn thing at NAPA for 18 bucks and they won’t take it back because it’s an “electrical” part.

Is there a “shade tree” way to check the sending unit? Maybe toss it in some boiling water, juice one side and ground the other?

Any and opinions appreciated!

Scott