Low Coolant Light

[cornemuse]

I replaced the radiator in my '84 Blazer 6.2 & since then the low coolant light sporadically comes on, hot & cold engine. (level is not low) The new radiator is aluminium with plastic resevoirs on the ends (where the sensor screws in) I replaced the sensor, but this didnt cure anything. The sensor is plastic, so grounding isnt (shouldnt be) any issue.
Any ideas?

-corne-

Connector seems a tight fit.

 

[ak diesel driver]

Still sounds like a ground issue. Maybe follow the wires to a ground or clean the ones you can find

 

[just a number]

the ground your hunting for doesn't exist anymore. the rad itself was the ground. try running a ground wire right to the sensor body itself.

 

[WarWagon]

Not true. The sensor grounds through the coolant so radiator tank material is irrelavent. So any resistance or bad connections will trip the light. I have used both brass and plastic radiators ok with the light and the low coolant light is generally useless anyway. Too much crud builds up on them so when you have a sudden loss of coolant the light doesn't come on until the sensor dries off.

Did you clean up the sensor while moving it to the new radiator?

I would make sure you have a new ground strap between the body, engine, and frame.