Coolant Temp Light

[hetrickw]

My Water temp. light comes on (slowly) from dim to bright starting within seconds of starting the car and is fully bright within several minutes. It can't be high water temp that soon. I can run it for hours and it doesn't overheat. Radiator, temp thermostat, all new. I've tried several temp sending units tried, they appear to be good. Anyone give assistance on diagnosing (short, ground, etc.) issues with the wiring. Thanks in advance.

Bill

 

[imusa76]

make sure of the following.

if you have the idiot light in the dash, that you are replacing it with the ON/OFF type sending unit.

if you have a Guage it will ne a resistive type sending unit.

it sounds like you have the wrong sending unit at the engine.

 

[wwhite72]

Is your car a 73? The sending units for 70-72 fit all 351's but that model only works on 73's with guages.


Part 01075 at mustangs plus is the part you need $25 bucks

 

[Don C]

Sounds like you have a sending unit for a gauge, that gradually increases resistance. The unit for a light is basically an off/on switch that is activated by temperature, so light would be full on or off.

 

[hetrickw]

Sounds right. I'll double check and get the on/off type. I have a 1971 w/dummy light, should have explained in more clearly. Thanks all.

Bill

 

[imusa76]

Sounds right. I'll double check and get the on/off type. I have a 1971 w/dummy light, should have explained in more clearly. Thanks all.

Bill

let us know if that worked.

 

[hetrickw]

That was it. Needed a switch not a gauge. Thanks all.

Bill