Check the sender unit for the coolant level.

My coolant level is a bit low, but I don't have a problem with my light coming on. I've had it come on when we flushed the system (key in ignition, motor stopped) recently.

You might just have a faulty ground wire on the sender unit, or just some debris in the plug itself. I'd try that if I were you.

Don't take the dealers problems on you. He has a car running around with a faulty sensor, he should replace it for you!

I wouldn't like having such an important light come on and off like the boy who cried wolf. That would be completely terrible in the case your hose clamps comes off and drains the coolant. You would sit and think "oh no not that darn light again". If the coolant flushes fast enough you won't be able to see it on the temp gauge as the water pump can't pump water onto your temp sender unit. Temp would be fine and the rest of the engine boiling.

a couple of other folks had issues - sound like adding a little coolant helped.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=28733

Thank you! Some people think it may be the sensor is not calibrated right and brining the fluid level just over the fill line might make it work properly.

It's proabbly just a simple float switch - no calibration required. They can get stuck on if they are activated by low coolant. This can happen when the engine is cold especially if the weather is also particularly cold and it will mysteriously clear itself as the engine heats up. I had a vehicle that had this problem after the coolant had been drained and I drove around for a couple of weeks before the light finally extinguished. Topping of your fluid should fix it.