1988 M3 windows and gage cluster not working after dash removal

[BurgundyE30]

I'm working on a 1988 m3. Unfortunately someone who owned this car in the 80s/90s did a number on the wiring harness trying to install alarms/stereos. I took the dash out to do some clean up and when I put it back in the windows and the cluster no longer worked, both were working perfectly fine prior. Can anyone point me in the direction of what might be causing it? I'm by no means a wiring expert and I'm a little lost.

[jbontke]

There is a ground cluster near the gauges (bundle of brown wires), make sure its clean and gets a good ground.