u/Difficult_Isopod_124

I recently found a e36 cluster and thought it would be fun to rig up a dash for simhub. I have everything working…. but the speedometer. I am wondering if this is a code problem or a hardware problem where I will need to go into the dash and fix stuff. Basically. The speedometer will go up from zero to 60 but once it reaches sixty it starts coming back down to zero. Rewired it three times and tried almost everything. If anyone has any solutions that would be amazing. Thanks for taking the time to read.