Q: My speedometer doesnt not work on my 1990 BMW 325i however the odometer works fineand Temp gauge and Fuel gauge, sometimes the speedometer just tells the correct speed for like 2 seconds and then it jumps back down to 0. I think its a wire or the Si board but I am not sure, any suggestions on how to fix it?
A: HI ! First off.... The other answers are all wrong. PLEASE ignore them. I have seen this problem many many times in BMW's. The Speedometers Main Circuit Board has a bad Solder Spot. Remove The Speedometer and have it repaired by a proffessional or replace it with good used or new unit. I would have it repaied myself as it is easy and painless. If you lived in San jose California: I would charge you $120 to remove repair and reinstal with 2 year warranty...Would take me about 1 hour to do the whole job at you house or place of work or anywhere. I hope this helps..Good Luck!