errr
the coolant temp sensor runs off the thermostat housing stu as i told u on vvoc, the CTS also controls the dashboard gauge as well
the sensor inside the expansion tank is the for coolant level sensor for the TID / MID
the thermostat housing is located rear right hand side of head, just look for the water pump and follow the big fat silver pipe running alongside the head leading to the stat housing, only 1 sensor there and it is 2 pin
i also suggest u wait until engine has reached operating temperature and give the dash a tap above the gauge needle as they are prone to wear and sticking
