Temperature gauge install???

[bighermHK45]

I have a 1999 Merc 115 hp 2 stroke outboard and I would like to add a temperature gauge to my instrument panel. The motor has the alarm but no gauge and i would rather have feedback under power and not wait for it to overheat to be notified. Where can I install a sending unit on the motor that I can wire a gauge to?

I also have a tan wire off of the wiring harness that does not have a home in the engine compartment and I was wondering if that is for a temp sender?

 

[bighermHK45]

bump

 

[gm280]

You would have to get an engine schematic diagram to see what the tan wire was there for. If it is not used, you could adopt it for your temp sensor. But then mark it as that so down the road others will know what it now is. As for the placement of the temp sensor, again that depends on the type sensor. Some attach to the top of the head on the outside while others are threaded into the engine water passage itself. So it depends on what you buy for a temp sensor. If there is already a temp light, you could see if it is merely an open/close at a certain temperature type sensor or a progressive range resistive type. If a progressive resistive type, you could tape into that sensor for your gauge as well. So it really all depends on what you have and will buy to support your gauge.