Got my 05 sd on the road for the first time today, and noticed that the coolant temp gauge wont read at all over the 4 mile trip, oddly as soon as u switch the kill switch off then back on it reads 3-4 bars,

has any one ever heard off this??

cheers andi,

Haven't heard of it but I'd be checking the wiring in the headlight. Specifically where the sensor goes through the 12 pin plug.