speedometer/odo/fuel guage don't work :(

[peytonracer4]

on my '91 318is my speedo/odo/fuel gauge doesn't work. the wiring to the speed sensor looks old, but it's not damaged as far as i can tell. i replaced the speed sensor and still no luck. i was really hoping this was the problem
now i'm stuck. i've searched and everyone says when all 3 of these gauges don't work it's typically the speed sensor.
can anyone tell me what else this might be? i took the dash out and all the soldering points seem to be... ok. i don't see anything that's obviously wrong including the odo gears. those looks brand new.
any help is greatly appreciated.

[Nick_S]

SI board? My guages act a bit silly and my MPG gauge recently stopped reading right after I pulled my car battery. Was told it could be the small batteries in the SI board. I'm still fairly new to these so don't quote me on that.

[peytonracer4]

SI board? My guages act a bit silly and my MPG gauge recently stopped reading right after I pulled my car battery. Was told it could be the small batteries in the SI board. I'm still fairly new to these so don't quote me on that.

i was under the impression that the speedo doesn't run off the si batteries. but i could be wrong.