[njv]

hi
its a thermocouple and there is the hot end ie the ring that gos under your plug and the cold end is where the connector goes off with normal wires to the gauge itself.

now on a recent decent autobahn journy at 6oc i notice not for the first time my head temps reading about 35-50 f more than normal just recent outside ambiant temps have gone up to around 12 15oc and my cht reads what i consider normalof course with ambiant temps playing a part in the reading like this it tells me perhaps were getting a artificially low reading in the summer when its real hot outside!! this is possibly more cause for consern.

now your insrument learn where they normally sit on average any big deviations time to pull over is the way i look at it but typ4 i dont think you will be pulling over!