Help. I just bought myself a 900i modell 1988. I have no lights in the dashboard, and neither in the roof. I also expierience that the temperature goes straight up after a while, and then goes back to normal. Any ideas?
A lot of electrical problems can be caused by corrosion on the ground point at the front cross-member where the wires meet below the radiator. By cleaning that up, many issues are solved. The temperature is most likely fine (although check that your thermostat works, fan comes on and coolant level is enough), but the gauge could be acting strange - like this one. Also check the fuses and relays - these changed a bit on different model years, but it should be under the rear seat.