The brake lights work occasionally. Cleaned some corrosion on the 3rd light and got that working again. The hazard lights work but turn signals only work if I turn them on and off manually. Not the most convenient. When testing voltage I get 12v on the black/brown for tail lights but when I test black yellow on L or black green on R I am only getting @10.5.

All fuses have been changed. Do I need to remove the fuse panel and clean that? I can not seem to find a proper wiring diagram. The Haynes manual doesn’t even cover 1986. Can someone point me in the best place to start?

 

Sure you can check the voltage at the fuse; no diagram, but it'll be cryptically labelled something like "STOP/TS".

You might just need a new flasher. It'll be somewhere other than the fuse block. Probably the back of the dash near the steering column above your right knee, or in the "convenience center" (the tray looking thing the ODB1 connector is mounted to).