Right rear turn signal conundrum

[moshrider3]

Hi all, I've posted a few times here and am back with something maybe the more experienced members could help me solve.

Over the winter I did an engine swap from 305 to 350 sbc. Turned out I needed a transmission also and I had a 205 transfer case I wanted to swap anyway so it all worked out. I'm still working out the kinks and so far I'm having a lot of trouble solving my right rear turn signal problem.

So far this is what I have discovered:
All other headlights/blinkers/sidemarkers work.
The left rear turn signal and brake light function perfectly.
With the lights turned ON, the right rear brake light will light up.
With the lights turned OFF, the right rear brake light does not work.
I used a test light at the spot where the wiring from the front meets the wiring to the taillights and split off, and unless I did it incorrectly, I had power from each prong.
After using the test light I thought I had a bad socket and replaced it to no avail.

Does anyone have any wisdom they can share or point me in the right direction? I'm sort of at a loss of anything else to try. I also checked all of my grounds and cleaned them, unless I am missing one.


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[ehjorten]

Very likely it is your turn signal switch inside of the column.  There are actually two separate switch contacts and they are separated by the front and the back.

If you look here: http://forum.73-87chevytrucks.com/smforum/index.php?topic=11766.0 and look under what year your vehicle is...you didn't specify...look under Chassis and Rear Lighting.  You will find the Turn Signal Switch and can trace the circuits.

Also...typically the turn signal indicator bulbs are run off of the front turn signal circuits.

[bd]

Try a new 1157 bulb and make sure it is properly installed into the socket.  Check the rear lamp harness where it passes over the rear axle adjacent to the exhaust.  Inspect it closely for heat damage and melting.  What happens if you probe the R/R socket shell with a test light grounded to frame and the running lamps on?