I have an 04 plate st170 and a few months ago the temp guage and fuel guage would go to half way when the engine was switched off when the car was running the guages would work properly,now as the weather has got warmer the guages are both working ok but if the temperature drops they will resort to going to half way when ignition is off,also when you stop the car they will go to zero but if i return to the car sometime later the clocks are at halfway but only if the wheather has gone cooler,i have spoken to a ford mechanic who says it needs a new instrument cluster but then the milage is at zero and can not be altered to the correct milage for the car and i dont really want that. This problem seems to be temperature related,i have cleaned the earths and made sure the engine temp switch is not touching the ht leads.Has anybody experienced this same problem and does the instrument cluster problem affect the st170.