Tach not working. “Inspection” light won’t reset.

[Balocco]

Hi all,
I’m down to two non-working items on my 1989 325i. Everything on the instrument cluster, and all other electronics work except the tach doesn’t move at all and I can’t reset the inspection light. The number 10 fuse appears not to be blown but I have not yet replaced it. Would this be an si board issue with so few missing gauges? Seems like there would be more issues if si board battery is dead. Any help much appreciated! Brian

[superj]

That fuse is the reverse light, I believe. The wire under the shift boot is rubbing something.

The inspection light, did you jump the pins in the diagnostic port above the alternator?

The tach sounds more serious

[Balocco]

That fuse is the reverse light, I believe. The wire under the shift boot is rubbing something.

The inspection light, did you jump the pins in the diagnostic port above the alternator?
I did jump them to no avail.
The tach sounds more serious

Maybe I need new tach?

- - - Updated - - -

I did jump the pins but it didn’t reset the inspection light. Maybe I need a new tach. Thank you

[richardodn]

The SI board batteries in the cluster are the issue with both the reset problems and tach.