All right, an update after some investigation.

I pulled the instrument cluster and cleaned all the contact points that I could access, I found one burned out bulb, emergency brake light. I also checked the bulkhead connector, it was tight with no loose wires.
The issues was better, but still there. As I was putting the ground back on the battery, I told myself to check all the ground to vehicle connection, the very first one was battery to engine. At first it look good, but I decided to pull it off and clean the surfaces. Upon loosing the bolt just a little, the cable fell off. The end connector was broken in two places. I put a new end connector on. I found one other body ground from body to transmission with a bad end as well. Cleaned all other grounds I could find, I fixed a bunch of wiring connections from previous owners, trailer brakes (wired with Romex wire), stereo and trailer plug that were only held together with twist ends and electrical tape!

For now the issues has gone away and the seat belt indicator buzzer has decide to work, but will probably get unplugged soon.

Thanks for all the help!