'87 35hp temp switch question

[don_61760]

Hello! I'm new here and have a question about my 87 35hp merc outboard. On the cylinder head right next to the top spark plug there is a sender of some sort. A local dealer said it was a temperature switch but he didn't know if it was for a gauge or an alarm. I'd like to hook up a gauge if it will work. Anyone have any idea?

 

[racerone]

A switch would be for an alarm.----A sending unit would be for a gauge.----So see what your ohmeter shows you in water coming to a boil.--Careful as it is a pricey item.

 

[don_61760]

Pricey is an understatement. $300+ on marine engines.com. Can that be possible? I think I'll just leave it where it's at. Left with a water pressure gauge or maybe put a sender in the 1/8" pipe fitting. Any recommendations?

 

[Faztbullet]

That is for a hot alarm horn not a gauge...