Here's a new one for everyone to chew on.


I bought my truck from a salvage yard, rebuilt after a small underhood fire. runs good and no problems from the fire except that my low coolant light stays on. I have disconnected it at the switch and check it out to make sure thats does not appear to be the problem. checked wire under the dash everything looks ok there too. Does this signal go thru the computer or somewhere else before going to the dash. any idea's out there?

Isn't the low coolant light on the low side of the radiator reservoir. Mine comes on when the level drops. I would think you could disable it.

i believe the sensor is in the placstic reservoir on the pass side up by the firewall. If there is another one somewhere I have not found it yet.

the sensor wants to see a closed circuit. harness is on reservoir. pull plug and jump terminals w/short piece of wire then forget it. the sensor does pull out of the res. works like a contact for a home security system. small glass tube w/metal plates inside that make contact when a magnet is near. one stealer(chevy) told me that you had to replace reservoir and the other literally next door(gmc) sells just the sensor. go figure.

I have this problem intermittently even though the coolant is always full. I have not yet investigated this problem but have a theory.


I also have two headlights that are intermittent and upon examination of the connectors at the bulbs I see that the metal prongs ar green with corrosion and all it takes to get the lights to light is to wiggle the connectors. I'm figuring it's probably the same thing.

I knew i read this somewhere else.

After putting my 00 back together and running about 90% water my light stayed on also with everything full. As soon as i changed it out to -20C Dexcool the light went out and hasn't been back. Just a thought...

I knew i read this somewhere else.

After putting my 00 back together and running about 90% water my light stayed on also with everything full. As soon as i changed it out to -20C Dexcool the light went out and hasn't been back. Just a thought...
Thanks :)

Mine is always on to, even though it is full. I changed it out with Dexcool, and it is still on. I do have a small leak, I mean very small, do you think it can feel pressure to? I was thinking that mine was on because it wasn't pressurizing like the sensor would want it to? Just a thought?

I have been told that the sensor in the over flow tank, where the light signal comes from, go bad otfen. Not totaly sure it it's any open or closed signal system so don't know if unplugging it will cure light or jumping the plug will. Any one else know

Hmmm.... The new Dexcool did it for me, i was thinking the sensor needed a certain amount of resistence to turn the light on/off and just plain ole water wouldn't do it. How old is your antifreeze?

Take a volt meter and put one end on the negative battery post and the other in the fluid tank, mine reads about 0.3v, if your nearing 1.0v the stray voltage may be playing havok with the sensor, or just try a new sensor.

had that same thing happen to me and still do from time to time. I just check the fluid if okay forget about the light, if low add water. BTW i run 50/50 mix.