OK, so I got my new turn signals in, now it's time to wire them. The painters just cut the wires but there's a portion of the wiring running in within the hood. So I have the original light blue, dark blue, and violet wires.

I took the wiring diagram from the manual and "erased" everything I didn't need. Here's the pic:
1964_GMCwiring.png http://captaincheeto.com/pictures/64-gmc/turnsignals/1964_GMCwiring.png


I wired it up just as shown here. Here are my results:
1. I have no parking lights (but the rear lights do work in parking mode.

2. When I engage the left signal, BOTH signals blink bright (bottom bulb filaments).

3. When I engage the right signal, only the right one blinks, but dimmer (using the bottom filament).

In both cases, the turn signal indicator on the dash blinks.

I'm pretty stumped. I removed the light blue wire from the firewall, and got the exact same results. If I remove the dark blue wire, both blink for left, netiehr for right. The dash indicator still works for both. If I remove the violet wire (supposed to go to the light switch connector) then I get nothing.

Now the ONLY thing I didn't do per the diagram was have the violet wire connected at the left light and then to the right light. But they're connected together, more in a Y... i.e. the wire comes from the firewall to the middle of the hood, then does a Y to both lights.

OK wiring gurus, what's going on? It appears I have the original wiring, so I would expect it to all be intact.

There is one place that you have not looked, and it is there - only there - that you shall find the master.