66 dart with no lights

Just picked up a 66 dart that has no lights except for the turn signals front and back. When I pull the light switch there is a little red light comes on the dash but that's it. I'm not sure about reverse lights yet but I have no brake lights.

I'm not sure where to even start on this one, it looks like a lot of the wiring has been messed with over the years but so far I've found nothing broken or too obvious. I would like to start new and get a whole harness but the wallet says no right now, so if anyone has some advice to start diagnosing I'd appreciate it