these can be fixed fairly easily . first check the fuses and the conector under the fuses. second you might have a bad SI board (dead or needs batteries) rebuilt one are around $200.00 or get a used one that you can take back if defective. these board are the same in a 82-88 5 series,
82-89 6 series and the 82-86 7 series.

do any of the other instuments work ? i can also give yopu detailed instructions on how to rebuild your si board if you would like

mark baker

markbaker99@hotmail.com