Hi
Looking to add a hot horn to a 588 Dart Big Block. Almost all outboards have them, but not many inboards. Can't seem to find one on Teague or other sites. 180 degrees would be perfect. Usually it is a normally open sensor to a 12v horn, anybody make them specifically for inboards? Best place to mount sensor?

Thanks
Frank

mercruiser has a warning horn for overheat even for carb apps for many many many many many years now.

Don't know the Dart block but if you have a 1/4 NPT plug on the thermostat housing, suggest installing temp switch 48952. This temp switch is normally open and will close when it gets to around 200 degrees. Then connect the Merc horn () to the ignition purple wire, and the other side of the horn run to the temp switch.

If you have the standard Merc harness, this would be the Tan/Blue wire

https://www.mercruiserparts.com/48952-switch-assy-temp

Merc water temp sensors will set off the alarm around 200*

Thanks guys
Engine doesn't use a thermostat just a crossover pipe, so I'll either weld a fitting on the crossover or the Imco risers have a drain fitting I could probably utilize.

As always, thanks

Few companies make thermostat housing spacers with several tapped holes,.Brodix is one, Iknowt here are more.

Not going to see any heat on the crossover.

okay, good to know- thanks for info

Maybe I got a head ofmyself for coolant temp or temp alarm sensors. On a Vic Jr intake manifold, there are three places one can use. Does your intake have these ?
Maybe a good idea to show pics of your intake manifold and thermostat housing so we can see and discuss.

As you can see those holes are already being utilized

Ayuh,...... So put a Tee where the gauge sender is, for both, or drill, 'n tap the t-stat cover for 1/2" pipe,.....