coolant light

[jakeumfleet71]

just bought a 1971 mustang coupe with a 302. i was told that the intake was a 76 so it might be a 76 motor. my coolant temp light comes on shortly after starting the car,(minutes). i drove it several miles to get home and still drive it here and there and its not overheating. how do i get that light off and get an accurate temp reading?

 

[jbojo]

just bought a 1971 mustang coupe with a 302. i was told that the intake was a 76 so it might be a 76 motor. my coolant temp light comes on shortly after starting the car,(minutes). i drove it several miles to get home and still drive it here and there and its not overheating. how do i get that light off and get an accurate temp reading?

You probably should post this question in the maintenance and repair section of the forum. Sounds like you have the wrong temp sensor installed. For a light, the sensor is basically an on/off switch, for gauges the sensor is a analog sending unit so as soon as the temp starts rising it sends a signal and the light would go on. I'd check that first.

-jbojo

 

[jakeumfleet71]

just bought a 1971 mustang coupe with a 302. i was told that the intake was a 76 so it might be a 76 motor. my coolant temp light comes on shortly after starting the car,(minutes). i drove it several miles to get home and still drive it here and there and its not overheating. how do i get that light off and get an accurate temp reading?

You probably should post this question in the maintenance and repair section of the forum. Sounds like you have the wrong temp sensor installed. For a light, the sensor is basically an on/off switch, for gauges the sensor is a analog sending unit so as soon as the temp starts rising it sends a signal and the light would go on. I'd check that first.

-jbojo

sweet! thanks jbojo! ill try that!

 

[72HCODE]

well if you are sure the engine is not overheating my guess would be the coolant sensor for the 1976 engine has a different ohms reading then the original 1971 mustang coolant sensor.

being a 1976 that would be a winsor sensor. i don't know what ohms range that reads.

then you have a 1971 mustang idiot light coolant sensor which is different from the coolant temp gauge sensor.

So you would need to see if a 1971 coolant idiot light sensor can fit the same threads in the 1976 block, if it does you could swap the sensor and that should turn the light off.

as a hack, you could install a 5Watt lets say 10 ohm resistor inline with the current sensor that would increase ohms and might turn the light off but then it would be even less calibrated to when the light should turn on. i wouldn't do this.

I would start with ordering the correct 1971 part and then compare it to the 1976 part and see if it could even fit, or at least get a ohm meter on the sensor and see what the range is you can use a pot of boiling water to test the sensors.

 

[Don C]

The temperature switch (non-gauge) provides the ground for the circuit when the coolant gets hot enough to cause the contact in the switch to close. If the wire between the switch and the light has a ground (short) it will also turn the light on.

 

[jakeumfleet71]

The temperature switch (non-gauge) provides the ground for the circuit when the coolant gets hot enough to cause the contact in the switch to close. If the wire between the switch and the light has a ground (short) it will also turn the light on.

thanks all, ill try it all!