temperature sensor in the radiator on carburated festivas?

[festerzilla]

The temperature sensor that is in the radiator on carburated models, (but not in FI models) is that the temp gauge or the fan switch sensor? Please don't tell me it's the fan switch sensor, because I have to use a FI radiator in a pinch here and I just noticed the difference

[zoe60]

The fan switch is on the thermostat housing and the temp sensor is on the head. I've never figured out what the one on the radiator does. I'd like to know. The car may not run right without it so be careful.

[Damkid]

i highly doubt it would effect how the car runs, the worst that would happen is the fan wouldn't come on, if it doesn't turn on, wire it so it turns on with the key

[Damkid]

just unplug it as it sits and see if theres a change

[festerzilla]

I took it to work and back like that yesterday but I didn't sit in traffic enough to see if the fan was working. The coolant temp guage on the dash was working. If connecting the leads runs the fan I'll put a switch in one of those blanks on the dash, and never let anyone else drive the car

[WmWatt]

The Haynes manual says unplug the sensor in the thermostat housing and turn on the ignition key to make the fan come on. It's a quick way to test the fan and it's circuit.

It doesn't say what the sensor on the radiator does. In the wiring diagram it's called "coolant temp switch" (light green wire) and the one in the thermostat housing (thermoswitch) is not shown. What is shown is a coolant temp sensor" (brown wire with red stripe). The wire on the connector on the thermostat is covered so I can't see the colour coding.

I guess the thing to do is turn on the key after unplugging each and see which one makes the fan come on.

There's more stuff in the manual on diagnosing problems with the fan and temp sensor circuits with a volt-ohm meter.


BTW I drove to the public library today so have both the car and Haynes manual (kept in the car) outside in the parking lot while using the computer. Was able to go out lift the hood and lift the manual to check on this.

[5.0zone]

It called the "Radiator Temperature Switch" in the Ford manual but I haven't found what it does yet.
Its not for the fan (that I can tell) that switch in on the thermostat housing and the temp guage sensor is right next to that.

[festerzilla]

Thanks, I tested it yesterday and the fan works as it should, when the plug on the termostat is removed KO and when the engine is hot. It seems to work the same with the leads disconnected. My thought was maybe it was used on 88-89's w/ A/C. One of those wires has 12V BTW