anyone know why the low coolant light on an 89 bonneville sse is on? the cooling system is full. could it be a bad sensor?

Sure is. I have the same problem. I think it'* usually caused by the sensor being dirty... and cleaning can fix it.. but I have no clue. I sure would like to know though.

i would say the sensor....but where is it even located... :?

my 89 sse was doing the same when i first got it. if memory serves, the coolant sensor is about halfway down the left side of the rad(when you are facing the car). i put a new one in. it only cost a couple bucks from the dealer. haven't had a problem in the 20,000 miles + since. hope that helps!

yep, that'* where it'* at. I did notice one day I had the car idling for 10min or so and once I got on the road it turned off. The motor got pretty hot, about 3/4 on the gauge, since my fans won't come on, then once I got on the road and up to speed it came back on. I'm going to try cleaning mine one of these days... I had some cooling system problems on the old motor, and I wouldn't be surprised if mine were nasty.

For the time being, if the warning is annoying, disconnecting the sensor will turn off the light. It'* the opposite effect that conventional thought would assume.

to open source guy;

i don't mean to hijack the link, but my car normally will go to 3/4'* on the temp guage before the fans will kick on. it does this at idle or in traffic. the fans do go on. this isn't normal?

bill

Nope no fans, it'* the only thing that could explain my QDM code... everything else works.

Been there, done that also. Back in 2004.
Replaced the sensor, & the low coolant light went away.
Just buy the sensor at your local parts store.
Cheap fix at home if you have the tools.