Ok, update on this whole fiasco...I've hade some headway but not solved it completely yet. The park lights DO work at half pull of the light switch. Turns out the socket for the passenger front park lamp was not connected into the housing too well, therefore wasnt grounded. It works now. Drivers side one still doesnt work. I think it may need a new socket, as the bulb fits in very loosely. The left signal issue...still haven't solved it completely, but have come up with this....the light housings are grounded by screwing them to the truck itself. They dont work once they're pulled off. The passenger tailight functions as it should...tailights, signal, brake. Drivers side one comes on when lights are turned on, goes out when brakes are pressed, and also goes out when left signal is turned on. Left front signal does absolutely nothing...but like I said, pretty sure it needs a socket. Now, the left tailight has been rewired at some point...ugly taped up repair job...and the socket appears to be incorrectly mounted into the housing. My hunch is that it was spliced incorrectly, and may not be grounding because of the socket being incorrectly installed. Gotta love fixing other people's screw-ups!
