Temp warning light

When I got my 73  the warning light stayed on for a minute or two after starting the engine. Although unsual I thought it might have gone out after the operating temperature was reached.

Now the warning light stays on all the time whe driving and as the light comes on right from starting the engine I am certain that it goes on without (good) reason.

I suspect a wire problem somewhere but dont know where to start looking and for what. Can the wire be touching ground somewhere? The wire from the sending unit is spliced into another one and wrapped with tape.

Any advice for me on how the warning light works and what to check?

bad temp  sensor

Disconnect the wire at the temperature sensor, if the light goes out it's the sensor, if it stays on it's a short.

Also, some Fords had a cold engine warning light as well. That might be why yours stayed on for a couple minutes and then went out. My 68 Fairlane 500 had it.