Temp gage with warning

[Todd Peterson]

I have a 470 mercruiser in a 1984 Beretta. Last year I overheated and spent $2k to replace all of the gaskets in the engine (nice paint job on the engine now). Is there a good temp gage out there that will shut down the engine or sound an alarm when it gets too hot?

Thanks, Todd

 

[Silvertip]

Re: Temp gage with warning

Does your boat not already have a temperature gauge? And does it not have an overheat warning horn? If so, do both of these systems work? These have been standard for years. I'm not aware of any gauge that will shut down the engine due to overheat. Your eyes and ears are the warning system. Gauges must be monitored but unfortunately many people spend more time looking at the gas gauge than the oil pressure and water temp gauges which are the two most important gauges on a boat as they monitor engine health.

 

[Todd Peterson]

Re: Temp gage with warning

I should check it out.
I did not hear anything, the engine just slowly shut off. I did get it turned off before it quit. Steam that came out of the dog house. I need to test or replace the gage or sending unit or check the wiring for a good conection and ground.

 

[Silvertip]

Re: Temp gage with warning

So it does have a gauge then? Chances are the gauge is not the problem nor is the sender unit on the engine. The wire that runs between the two may be the problem. The gauge also requires +12 volts when the key is on and it also needs a ground connection. A test light or multi-tester is the best way to troubleshoot electrical issues.

 

[Todd Peterson]

Re: Temp gage with warning

When I get it back from the shop and in get the alternator kit installed, fix the doghouse to except the new alternator, fix the motor mount beam and then take it back to the shop to have them install the motor mount, I will check it out. Then bring the boat back to the shop and have them winterise it for me and then put in storage for the winter.
Other than that, all is well.

 

[Henry Curd]

Re: Temp gage with warning

Hey, guys, trying to check out temp gage on Mercury xr2 150 hp 85'. Gage has "S" post with brown/blue tracer wire to cyl head, "G" post with black and gray wire, this goes to ground i assume, also has another post on gage to light up the back light on gage. My question is how do i test the gage and temp sending unit ? Thanks Henry

 

[Bondo]

Re: Temp gage with warning

Ground out the "S" terminal,+ the gauge should Peg, Hot...

 

[Silvertip]

Re: Temp gage with warning

That tests the gauge but not the sender. An outboard temp sender should measure 33 - 240 ohms but it must be tested in a pan of water. Measure it cold (room temp) and then dunk it hot water (boiling). Measure the hot resistance immediately after removal as resistance changes quickly.