Water Temperature sensor

[vrinner]

OK...so trying to figure out the last of a few things on my 1E stock motor install. Car doesn't have all stock stuff on it so just trying to figure out the best method.

Motor has what appears to be a Nason temperature switch on the lower intake. Seems like it's mechanical. It has two wires as opposed to the one.

There is a separate/aftermarket fan relay switch on the car that was working with a single wire temperature switch.

Question...does a two wire temperature switch have one side to the relay and the other to ground?

[k98dave]

Not sure how that would work. Do you still use the stock temp gauge or is that sensor for an aftermarket gauge?

The fan/AC module relay is under the dash usually just to the left of the steering col. Its a black box about 2" square with a straight connector. These were known to fail and usually melted the connector. You can still both the relay and repair connector kit.

[vrinner]

The stock sensor/sending unit has a much smaller size than the hole in this lower intake.The part number is a TT-F1A meaning 1" probe, 1/2" NPT Male and SPST-NO Circuit form...whatever that means.The stock sensor in the other "stock" intake is much smaller. Went to Autozone and Oreily and both have a stock sending unit as much smaller than the one I have and the hole in the lower intake.

[in2fords]

I could be wrong but isnt the one in the intake for the gauge and the sensor in the block for the fan/ecu?

[Chuck]

The sensor in the intake is definitely for the fan circuitry...

[Raven855]

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Vince, the coolant temperature sensor is in the upper part of the lower intake. It is located between the fuel injectors and is connected to the computer and tells it what the coolant temperature is. The sensor is the same for the 84-early 85 inline manifold and the later square intake. The fan control switch is located on the under side of the lower intake and it turns on the coolant fan on the radiator. The 84-early 85 switch is a single pole push on type connector. The later square intake for the 85.5-86 has 2 spade connectrors. It is also a larger diameter. The second connector is simply a ground, whereas the early model is grounded through the engine. The dash gage coolant temperature sender is located on the block. Sorry don't have a picture with me of the later style fan control switch. It makes a difference what you ask for at the parts counter.

[MikeFleming]

The sensor for the dash gauge is on the upper rear part of the block, immediately under the Oil pressure sensor on that one inch hex block in the head. Single wire, push-on connector/stud (that's part of the fuel injector harness, btw).

Pics of dash gauge sensor hole (1/4 pipe). With/without paint.
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[vrinner]

Thanks...just took the two wires, one side went to ground and the other to the after market relay...worked perfectly. Although mine is on the side of the lower intake and not below where the coolant line is as per picture above. Thanks!