Tachometer and onborad computer won't work :mad:...

Hi there

I have a 88 528e which in the past has had the fuse connection for the tachometer, onboard computer and odometer go out (also the stereo, but another owner changed the original hook up I believe).
I had repeatedly tried fuses and working with the connections, but as of late, I think it might be done.

Does anyone have a troubleshooting idea?

Thanks for any suggestions.

Ken Wood

Originally Posted by CanadianE28

Hi there

I have a 88 528e which in the past has had the fuse connection for the tachometer, onboard computer and odometer go out (also the stereo, but another owner changed the original hook up I believe).
I had repeatedly tried fuses and working with the connections, but as of late, I think it might be done.

Does anyone have a troubleshooting idea?

Thanks for any suggestions.

Ken Wood

Corrosion, particularly on the instrument cluster or the connecting wiring could be a problem. A bad SI board will usually blow the fuse for the computer and tach. Search "SI board". The odometer might be a separate problem with worn gears, rather common with older BMW's. Older cars start having lots of electrical issues. Check the connections and wiring very carefully. Sometimes the corrosion is inside the insulation where it can't be easily detected.

Thank you Catso, I will look into the wiring. That sounds very logical. In the past I have jiggled or moved the fuse and it works fine. Now, nothing.

Originally Posted by CanadianE28

Thank you Catso, I will look into the wiring. That sounds very logical. In the past I have jiggled or moved the fuse and it works fine. Now, nothing.

The fuses and fuse holders are known problem areas. Sometimes a fuse looks good but still doesn't work due to a small crack, looseness, etc. Try changing the suspect fuses with new ones and clean the contact areas.