Tailgate Wiring Harness from a '95 Bronco with defrost.
The round white connector was introduced for the frame connection in '92. From ~'87-91, the t/g wiring was integrated with the taillight wiring and used an 8-pin round connector at the frame. Before that, the 3-blade connector was behind the L taillight, with an extra 1-blade connector for defrost power & a ring terminal for defrost ground. The white style shown here is inboard of the L frame rail between the bumper & the gas tank rear crossmember.
Before ~'83, the interlock switch connector was at the center mechanism, so it was on a take-out near the motor connector. To bypass the interlock (meaning that the glass can be moved when the tailgate is NOT aligned with the camper shell), just install a jumper wire between its terminals. But it's better to leave it working properly and align the tailgate so that the L latch works properly. For a writeup on installation & alignment, read
this thread.
To add a simple self-diagnostic capability, wire a 12V lamp across the latch safety switch terminals, and mount it in the tailgate shell above the lock cylinder in the inside sill (through a carpet retainer hole if present). If either control switch is activated, and the only thing preventing the glass from moving is the safety switch, the lamp will light and be visible to a person using either switch.
