1990 right rear turn/hazard/brake lights not working
We have a 1991 Rexhall Airex on a 1990 chassis. Rear lighting consists of a 3-unit fixture on each side. The left and right units on each side have dual filament bulbs and are used for brake, turn, and hazard functions. (The center unit on each side is for the backup light.) The parking light and backup light functions on both sides work fine. The brake/turn/hazard function (second filament) on the right side does not work (left side works fine).
I have traced the wiring as far forward as the connector just behind the front wheel on the frame and find no power to the orange wire with light blue tracer which feeds the right rear brake/turn/hazard filaments. Due to multipe branching of the wiring harness forward of this connector, I haven't been able to trace further. I do have the owner's manual which shows the under dash fuse block. The fuses check out to be O.K. and just to be sure I've changed the two thermal flashers to heavy duty electronic flashers with no improvement.
I'm thinking there is a relay somewhere up front that controls this circuit but haven't been able to find one.
Any ideas, first hand knowledge, or even an electrical chassis diagram for 1990 available?
Thanks for any help, Terry