I have '88 e30 316, and a problem with my temperature gauge. When I start my car it starts to go out of blue area, and then it starts to jerk to left or right. Car was not driven for ~7 years, and as I remember it used to sit vertically when engine is at normal running temperature. Now it is about half way from blue to vertical, and jerking from time to time.
I changed dash panel recently with a used one, and it still jerks. Yesterday I changed temp sending unit - still jerks.
Perhaps there is some bad contact somewhere. I wanted to test it with my old dash panel, but I can not figure out which wire to connect to what. I have Haynes, Bentley and some German manual for e30 and none helped.
I took dash panel apart and it seems that one connection goes to the blue connector pin 26, and other two (ground and other connection of the temp gauge) go to the board that controls green, yellow and red service lights.
Can anyone tell me color code of the wire where to connect +12V, where ground, and where temp sender?
Or perhaps this is some common fault and known solution?