Gauge Cluster Issues, Where to start?

[D-n-Tyke]

So final got the truck up and running and am now trying to figure out this gauge cluster. Have the temp gauge, fuel gauge and the amp gauge hooked up. Speedo and oil pressure are not connected so of course those are not worrying at this moment.
The 3 hooked up gauges, temp, amp and fuel, all seem to be working, along with the both green arrows for the directionals. The problem I am having is when either of the directionals are turned on, the gauges go crazy. The temp gauge sweeps to pegged and then back to normal at the beat of the flasher. The fuel gauge stops working and slowly goes to empty. As soon as the directional is canceled things go back to normal. Additionally, when I turn the headlights on I loose all the gauges. I thought it might be a bad ground but I checked the ground where it attaches to the back of the metal dash and where the wire goes into the harness connector and have solid ground at both locations.

I am not sure where to go from here. What to check next. Has someone else had this similar issue and what was the solution that fixed it.