Expert: Josh Fields - 5/24/2006

Question
HI my sisters has a 1897 bmw 325 and the fuel guage and temp guage stopped working. we have miss placed the manuel and not sure if it is a fuse or something else. any ideas? can you tell me which fuse to check or anything wlse it could be.

Answer
Steve,
 this could be a couple of problems.

 It could be that the fuel sending unit, and the temp sensor both went out at the same time, but that is highly unlikely, so we'll rule that out for now.

 It could be the Service Indicator board has gone bad.  This is the little green/yellow/red lights that tell you when you need the next service performed.  There is a circuit board with batteries on it that go bad.  You can go to radioshack and replace the batteries (they look like AA batteries).  However, these have to be soldered onto the board.  So if you have any issues with this, take it to a TV/VCR or electronics repair shop and they can solder the joints for you you.

  The last possibility is the main board is bad.  The main board is what all the guages plug into so they can get power and signals.  The fuel and temp gauges are notorious for going bad because of this.  The temp/fuel gauges have a single threaded stud that screws through the back of the instrument cluster.  There are also two other studs that are not threaded, and they slide through some metal contacts.  If any of these are not making good connection, they the guages will not work.

 Hopefully this will solve your problems
 Josh