old burban stolen, and questions about turn signal wiring on new burban

[DRASTiK]

well my 89 burban was stolen from my driveway two nights ago. It had a lot of valuables inside it, and it's probably in a chop shop in Mexico somewhere!!!!

anyways, I went and got an 84 1/2 ton 4x4 burban yesterday, and the turn signals don't work properly. If I cut the left blinker on, it works fine, but when I cut the right blinker on, the LEFT one comes on again. In other words, all I have is a left turn signal and no right signal. I don't have a wiring diagram for this year yet and I was hoping someone out there could help me out with this problem. What wires am I looking for. I'm assuming that they are crossed somewhere or maybe the switch has gone bad. Any thoughts are appreciated.

Thanks in advance,
Dave