Water temp sending unit

Discussion in 'Engine/Drivetrain' started by Ivey, Feb 2, 2021.

  1. Ivey

    Ivey Veteran

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    I've been tearing through all my little projects now, next is to fix the temp gauge. So pictured is what I think is the (2) Water Temperature sending unit and the (1) Thermo switch. I tried grounding both wires and got nothing on the gauge. I traced both back to the main harness but its pretty well chopped up so I wonder if signal is even getting to the gauge. Am I right about the sensors? Also what the hell is a Thermo switch. I see it referenced once in my Chilton but just in a diagram.
     

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  2. jetas

    jetas Grand Toyotaholic

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    Pretty sure #2 is the wire you need. Just run a new wire to the gauge from there.
     
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  3. Ivey

    Ivey Veteran

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    Got this fixed or at least the circuit is fixed. I pulled the wiring diagram and the dome light is part of the circuit which I had disconnected when removed the rear view mirror. Connected the two wires for the dome and I’m able to get the gauge to move by grounding the wire. Still need to wait until I’ve got my headers back on to tell if the sending unit is working.
     
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  4. Ivey

    Ivey Veteran

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    Oh and #2 is the water temperature sending unit. #1 (thermo switch) turns on the warning light if the engine overheats.
     

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