So I bought an 88 GTA with the digital dash. The speedometer is stuck in km and won't change when I press the e/m button. The odometer and it's 4 buttons light up, but do not function. Also, the speedometer will show random speeds when driving. Does taking out the cluster and cleaning the contacts usually fix this issue?

Also, my power Iocks, mirros, interior lights, and cigarette lighter do not work although there is 11.8 volts at the fuse. I'm confused on why it would not have power. My hatch motor also does not work. None of my fuses are blown, could it be a relay?