For my Sierra '05 Sierra CrewCab - I don't have power to the trailer's left and right turn circuits, or stoplight. At the I/P fuse panel, for the Left and Right Trailer circuit, and with the ignition key in the ON position and turn signal activated, there is no power to the HOT side of each trailer turn/stop circuit. Fuses are good and the grounds are good. The main turn signals work.

I've tested the splices at the rear and they're solid and dry.

What links the main turn signal circuit to the trailer turn signal circuit? Is there a relay, module, or fuse (other than what's in the I/P for the LT/RT TRLR or engine fuse panel), or fusible link somewhere?

It all worked before.

Thanks