Temp Gauge Mystery Solved

[OldNBold51]

After chasing the problem of my temp gauge not working, even though all the tests for the sending unit and temp gauge showed individually they worked, I finally got the gauge to work!!!!

The previous 2 sending units were aftermarket units sold over the counter by my Merc dealer. This time I bit the bullet and bought an OEM Mercruiser sending unit and viola....I've got a gauge that shows my engine holding temps at 170F.

Thank God for the alarm working as middle of last summer the raw water impeller shredded.

Now, if I could just get the gas gauge to work!!!!!!!!!!!!

 

[mastercylinder63]

Re: Temp Gauge Mystery Solved

Greetings, I think I may have to same problem as you did. I know that my Faria temp gauge is working fine because I switched it with my port side gauge. I'm running two mercruisers 4.3 Anyway I touched the temp sending unit wire directly to ground and it pinned the gauge as it should. I removed the temp sending unit and replaced it with a Teleflex 52320S009 3/8" unit. Hooked it up and still doesnt work. I removed the sending unit and took ab ohm meter to it. Cold it doesn't show continuity. I put the sending unit in hot water, it shows full continuity. So I know the switch works. Is this what happened to you?? Thanks

 

[OldNBold51]

Re: Temp Gauge Mystery Solved

yes, I did all the checks as you just described to no avail. The original non working unit tested good but I bought another aftermarket one that tested good as well. The gauge, when grounded, completely pegged on hot.

The mercruiser sending unit worked. I also cleaned the threads on both the sending unit and the housing very well with a wire brush (a battery terminal cleaner tool). I don't remember doing that with the previous ones.