93 ZJ Limited dash wiring help

[Da XJ nut]

I've got a 93 ZJ limited 4x4 that has some electrical gremlins living under the dash, I need the infinite wisdom of the group to tell me where the dash harness ground points are located that have something to do with overhead display, VIC and the dash gauges( temp) does not work. I've looked for info and tried to locate myself but haven't been lucky yet, I've fixed 2 wires in the boot between the drivers door and body that fixed a small issue but not my crazy issues once it gets under 50 degrees outside, after that temp the speedo never goes over 20 mph even if I'm cruising with traffic over 60 mph per cell phone GPS speed app. Also the temp actuator doesn't work all the time and radio looses antenna strength when I turn headlights on. I've replaced the battery, Cables and upgraded those to 4 gauge wire and went to LED bulbs in headlights. I need direction and have searched for info within this site without luck. Hoping the other members have run across something like this cause I'm ready to sell it and dump that money into my XJ instead of wasting time chasing issues on the ZJ.