Turn Sig Switch - '69 912
 

After replacing my battery last year on my '69 912, my turn signal switch stopped working; it does not turn on the left or right signal lights (nor the dash indicator light) when key is in "on" position and switch activated. All other lights work, including the emergency flasher (relay clicks too). After looking at others' posted solutions on this forum back to 2000, I have done the following:

1. cleaned all fuses and light contacts
2. checked all grounds, including ignition body ground straps
3. sprayed DeOxit on switch contacts, capacitor pots, signal relay
4. switched around the three silver pots in the trunk to confirm that they all worked
5. switched out the turn signal flasher with two other purchased ones to confirm its operation is okay, then put original back in since it worked fine for flasher.
6. tested the flasher relay by pulling it halfway out and testing circuit 49a to confirm that it was flashing. I tested "C" to make sure that it was ground. The other two pins: I do not know what they do.

I'm stuck at this point. I am thinking that the turn signal switch is bad: the headlight functions work on it while the turn signals don't. Everyone who is selling a turn signal switch replacement lists it as "used" and "untested." An untested part with no guarantee - great... However, I went below the dash and have marked the connectors in case I need to pull the signal switch and replace it.
I am stuck at this point and would like to solicit some advice before I buy a used and untested part from God-knows-whom. And, to be frank, I am not very skilled with electrical debugging. I can operate a test light and an ohm-meter, but I am at a loss on how to track things down.
Thanks,
=rds