What Sensor is this Beside Cyl#1?

[WinnipegBoatMan]

Hi all!
Got a pic here of my almost finished '85 Tower of Power 115HP Mariner.
But ive got a question for everybody! What sensor is this?? Is this a Cylinder Head Temp sensor? If it is, why was the original wireing connected to the auto blend unit?? Or did someone have their hands on this bugger?

 

[Faztbullet]

Re: What Sensor is this Beside Cyl#1?

That is a overheat sensor and yes it was tied into the autoblend system as they shared the same warning horn.

 

[WinnipegBoatMan]

Re: What Sensor is this Beside Cyl#1?

Is this sensor then a "RTD" or just a temp sensor when it reaches a "setpoint"(overheat) does it close the circut? I'm wanting to install an engine temp sensor?
Also since i'm on the subject of electrical, how can I wire up my tach on this powerhead? Its a newer model, with the commander console. I haven't really got to the point of finishing off the powerhead, but would like to know if the wire bundle incudes a tach wire in the harness, maybe even a temp sensor??