Temp Gauge not working

[LanceD]

I've just purchased a 1999 Mastercraft Prostar 190. Took it out for the first time and realized that the temp gauge isn't working. There is no reading at all. After giving it ample time to warm up, I set out to use the boat. At no time was there any reading (needle was always on the far left)

It's my guess that it is either:
1. the gauge
2. the temp sender
3. the t-stat.

My guess is it's the sender. From reading/googling, I think I know where the sender is. It is in the front of the engine, slightly off to the port side. there is a brown wire attached to it. There happens to be a second brown wire buddied along side this wire that doesn't attach anywhere (? is this normal).

I get the impression I need to determine via hot water if the sender is working. This may be a silly question, but the sender, if I know the correct item, seems to be painted black, similar to the engine itself. Is this normal? Is it okay to take it out?

Can anyone give any suggestions and/or hints?

Thanks,
Lance

[rholmes]

I'll bump ya. I know on my older boat, it was a simple issue of removing the connector on the temp sensor and cleaning the contacts, put it back together and it worked fine.

[76S&S]

Try replacing the sender first. Inexpensive and easy to change.

[Muttley]

I'd say it was the sender. You can test the sender by removing the wire and grounding it to the motor with the key on. That should peg the gauge and set the alarm off.

The sender usually isn't painted... at least it wasn't on mine. Mine is like a brass plug into the top of the motor with a wire to the top.

[Jorski]

Replaced mine on an LT1 several years ago...original part was painted black, same as the block. The replacement wasn't painted.