Stumped

[Conundrum]

I was helping my dad with the 1ton he just bought, we were trying to get the tail lights, turn signals and brake lights to work. The right turn signal is all that worked when you turned on the left turn signal, when he got it. When we got started the wiring was a mess, so we removed alot of wiring and tied into the factory wiring that is back there and got the left brake light and turn signal working but that's all that works back there. I checked the fuses, we changed the flasher (that's when the turn signal started to work) we found a broken wire up by the firewall and reconnected it and we still didn't have anything on the right.

Anyone have any ideas of what might be going on?

He is wanting to take this truck to pick up a parts truck for it next weekend so we are trying to get it fixed as soon as we can.