Water Temperature Sending Unit

Happyguy52

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I have a 1996 Mercury 150 hp EFI, is there a port to install a water temperature sending unit for a temperature gauge in a water jacket? If so where would it be located? Thanks in advance for all your replies.
 

Dukedog

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for water temp no.. ya gotta drill it yourself.... here's one place. jus make sure it clears tha t-stat.
 

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Chris1956

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My '93 Merc V6 came with a overheat sensor on one head and a temp gauge sender on the other. You might check your heads. Maybe you have a plug, if no sensor.
 

Dukedog

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My '93 Merc V6 came with a overheat sensor on one head and a temp gauge sender on the other. You might check your heads. Maybe you have a plug, if no sensor.
thats just a metal ta metal sensor.. he's askin' 'bout an actual water temp sensor tha way i read it?
 

Dukedog

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if ya just want a merc gauge sensor you should already have one on tha port head.. there is a three wire sensor on tha port head jus under tha top plug that should have a tan wire that goes no where or plugs into tha wiring harness on tha "boat" side on tha motor.. it only reads metal to metal though.. its a three wire temp sensor that also reads temps for tha efi (two tan/blacks that got to tha efi stuff)... if tan is already plugged in to tha harness then all you need ta do is find it under tha dash and/or at tha control box.. will jus plug in to tha merc temp gauge
 
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Happyguy52

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if ya just want a merc gauge sensor you should already have one on tha port head.. there is a three wire sensor on tha port head jus under tha top plug that should have a tan wire that goes no where or plugs into tha wiring harness on tha "boat" side on tha motor.. it only reads metal to metal though.. its a three wire temp sensor that also reads temps for tha efi (two tan/blacks that got to tha efi stuff)... if tan is already plugged in to tha harness then all you need ta do is find it under tha dash and/or at tha control box.. will jus plug in to tha merc temp gauge
While I was figuring out what was wrong with the tachometer (dead), there is a gray wire that starts at the voltage regulator (top one of two between cylinder banks) to the tachometer. I will look for another gray wire.

I was thinking of installing your run of the mill temperature gauge for engines.
 

Happyguy52

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shouldn't be "another gray wire".. tha temp gauge wire will be tan...
I don't know what is with me but I read it as a gray wire or read it as tan but in my head, it clicked over to gray.

When I was trying to get the tachometer working I remember there was a tan wire under the dash.

Would a regular digital temperature gauge work and what would be a normal reading of head temperature once warmed up and temperature when it is getting in the danger zone?
 

Dukedog

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I understand for sure... got a lotta dead brain cells in this 'ole noggin' myself... temp gauges (tha ones that read metal ta metal) are tha worlds worst as for being anywhere close ta accurate so there's that... a merc gauge would get ya as close as possible but even then ya really need a temp gun ta see jus how close it really is.. a water pressure gauge and tha warning buzzer are really tha two main things ta have and trust............. jmo.
 

Dukedog

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JAN.. in case your warnin' buzzer/horn is remotely mounted under tha dash and not in tha shifter control box it could possibly have a tan wire goin' ta it.. should be a tan/black but not always.. some seem ta have escaped with a plain ole tan to 'em.. leave it be.. should be a tan thats not terminated anywhere that can go to tha guage..
 

Happyguy52

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JAN.. in case your warnin' buzzer/horn is remotely mounted under tha dash and not in tha shifter control box it could possibly have a tan wire goin' ta it.. should be a tan/black but not always.. some seem ta have escaped with a plain ole tan to 'em.. leave it be.. should be a tan thats not terminated anywhere that can go to tha guage..
I might have to drill and tap a sending unit in behind the thermostat. I'm sure I have the drill bit and tap.

There is a buzzer under the console that cherps when I turn the key to on.
 

Chris1956

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On my '93 V6, one could pull a threaded brass elbow out of the thermostat cover and install a tee and sender. You would not know temperature until the thermostat opens, but you would see her overheat, if the 'stats are good.
 

Dukedog

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I might have to drill and tap a sending unit in behind the thermostat. I'm sure I have the drill bit and tap.

There is a buzzer under the console that cherps when I turn the key to on.
thats 'bout tha only way ya gonna get actual water temp... thats also tha easiest place ta do it.........
 
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