E30 m3 speedo and odo not working

[325is_MadBimmer]

ok so on my brothers e30 m3 the speedo and odo are not working anymore. he put in a regular e30 cluster and they work fine. so we narrowed it down to the cluster.

now i know the stripped gears will cause the odo to fail, but what could cause the speedo to not work?

[86espowa]

cracked si board.

you need a new one!

[325is_MadBimmer]

can i just get the SI board or do i need a cluster?

[Court M3]

you can just get the si board or check yours for broken solder joints.

[Mtriple]

The car is toast, he needs to sell or trade it to me...

[Jscotty]

One thing that I learned the hard way was that I needed to re-heat the soldier joints and add a little bit of soldier to it. Sometimes you might get an invisable crack in the joint and even though it appears to be intact, the connection could be broken.