I finally finished the wiring for the lighted T yesterday, after having been out of commission for such work for about six months ... Just a few points:
My original problem was that the Posi-tap connectors didn't make decent contact, despite having been lauded as the best way to splice automobile wiring. Inspecting the connections in bright daylight showed that the headlight wires had been displaced sideways instead of penetrated. Yesterday, re-doing the connections was simple, and I suspect that the temperature had something to do with it, yesterday it was upper 80s here, and my earlier attempt in January was in mid 50s weather, which made the insulation stiff and hard to penetrate - just my best guess.
After the discussion with the DRL turning off with the headlights on I had installed diodes to feed the T from the headlights and DRL, respectively. Because of the dimming of the left DRL with the left turn signal on I had planned on feeding with diodes from the left and right DRL. When I tested that last evening before finishing the connection I found that the T does not noticeably dim with the turn signal on, so I ended up skipping the right DRL diode circuit.
Seems to work great now, just in time for TMC Connect
Thanks for the great additions to our beautiful cars, artsci!
Just ordered the rear red T ...