Front turn signals not working

Got home today and had some time to do a preliminary check, and here is what I found, if anyone has any thoughts:

1. Grounding the light socket and/or the parking light housing direct to the negative terminal of the battery did not produce any signal in the front. Not sure if this is the proper way to test if poor grounding at the radiator support is the issue, but if not, some direction on how to better check this would be appreciated.

2. I then pulled the harness off at the bulkhead, connected negative to ground and tested ports V, U, T, S, W, X, Y (z is blank) coming out of the bulkhead and found the following:

U is the only port that has 12v power when the parking lights are on
U and Y have 12v when headlights are on full.

S and V have no power with lights off and signal switch turned either left or right. Same with hazard switch on - no power

V does have flashing power (between roughly 3-12v alternating) only when the right signal is on and the parking lights are on. It has no signal when lights are off.

S has no signal under any of the above conditions...

Any thoughts on deciphering this crazy mess, I'm open to suggestions as to what to try next. I'll pore over the wiring diagrams later, figured I'd get this out there while it's still earlier in the day...