Temp gauge wiring (can't find my diagrams)

[pyro]

I lost my service manual, so fill me in.

The dealer replaced the temp gauge with a jackplate gauge in 1989 when the boat was set up new. I took out my trim gauge (I honestly don't use it) to put temp back in.

I'm sure I have the gauge itself hooked up right. Purple power, black ground, and then there's the sender wire.......
Temp sender appears to be tan wire under motor cowling. No tan wire under the dash, but there's one coming out of the control box, so I connected that one to the temp gauge. Why doesn't it work? Is this the right wire? What kind of resistance should I be looking for on the temp sender wire to know if it's working?

[Liqui-Fly]

Pyro the tan wires from the warning module are for the horn only (intermittent; beep beep beep). You have to have the appropriate sensor installed in the head and run a wire to the dash for the gauge. Or if you disconnect the warning module you could use the tan wire or tan and blue to get the signal up to the dash. If you need more than this I can elaborate with a pic later if needed. Usually the warning horn wires all run to a bus above the switch boxes. You aren't going to want that for your head temp sensor. The easiest way would be to use one of the four available pig tails from you wiring harness, if there are any available, and pick the signal back up at the control. You could also use the rim sender wire since you aren't using that. Sorry for the scatter reply...just thinking out loud.

David

[pyro]

Doesn't the head temp sensor have 2 sensors in one? One for the ECU, and one for the gauge? I see 4 wires: two for the ECU, one for ground, and another (plain tan) that goes directly into the control harness! There's two sets of wires on the control box: One is, of course, the main harness going to the engine. the other consists of wires going to the dash: the main purple "on" wire, power (always on), ground, tach pulse wire, etc. There's also a plain tan wire coming of that set of wires, it looks like the dealer had chopped it and looped the loose end around and tucked it into the tubing to hide it. this is the wire that I assumed would make the temp gauge work.

Do you know what the 'ohms' measurement should be for the temp gauge sender at any given temp?

[WATERWINGS]

When in doubt you can always run new wires, thats what I have done.

[Talon2.5]

maybe thiscan help????

[Talon2.5]

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[Talon2.5]

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[Talon2.5]

oh and maybe this one?

[bucket]

While on temp, On my 2.0 150 M on left side cylinder head at top there is a blank empty hole that look's to be for temp sender. Threads already inside. Whould that be a cylinder head temp hookup?????