[Roadsters] Wiring help needed, non-roadster

[Steve Harvey]

I'm befuddled in trying to figure out the correct wire hookup's for the rear
tail lights on a 21 foot 1979 Chevy 30 van RV.  Each side has two bulbs, a
single element bulb and a dual element bulb. I believe that each tail light
has four functions:

Running/head light

Indicator, left and right 

Brake light

Hazard light

 

I guess my first question is, what functions should the single and dual
element blubs on each side be  performing? The way they are currently wired,
when I operate the left indicator, brake and running/headlight's all is
well. When I operate the right indicator, not only does the right indicator
flash but the dual element on the left side flash's as well.  Very confusing
to me! I've wired plenty of roadster's with great success but this thing is
killing me. The interior of the RV has been gutted so I can see and follow
all of the wires to the back from above the driver's side door post. The
ground wires (white) also run from the front and appears to be grounded (to
the frame) correctly.

 

Steve

Milwaukee