stustrong said:

Definitely not its just 2 wires and a plastic float,

Click to expand...

Just read a couple of replies on another forum that back up my theaory.

1. The float rides at a different level depending on coolant/water mix ratio.... so if your coolant mix is wrong <50% it will show as a low coolant on the dash.

2. xxxx did a bench test to prove conclusively that you get low coolant alarm when filled with water, but not when 50% antifreeze is added.

Personally I'd change the coolant first since it needs doing anyway then change the expansion tank if it's still doing it.