I did look up the wiring diagram and found what I believe to be the proper fuses and checked, +12V on both sides on the right and left one (for the "marker lights" which look to feed from the same pin on the connector).
In-between is a "bulb tester", any chance it could be at fault?
edit: Am I reading this right... seems like the fuses involved show as S1 and S2 on the wiring diagram. There's an S1 and S2 going into the bulb check module, pins 5 and 7. Then pins 3 and 4 look like they feed the tail lights. I could try bridging 5-3 and 7-4 if anyone can confirm these are the ones.
