4.3L temperature switch

[joedee983]

I have a 1989 4.3L Mercruiser in a Dixie. It only has a temp sender for a guage. I would like to add an overtemp switch with a alarm horn.I have a 3/8 NPT stainless steel switch,but I can't find a place ti install it. There is only 1 tapped hole in the thermostat housing. Anyone know where the newer engines have the switch

Thanks
Joe

 

[Don S]

Re: 4.3L temperature switch

Look on the intake manifold on either side of the thermostat opening, you should see 2 pipe plugs.