Wiring Harness Voltage?

[pkirill]

I'm trying to determine the wiring in what I think is a trailer harness "outlet" (see my previous post... please?). I found the ground, and using my blinkers I'm trying to determine which of the other three pin receptacles is which. I found the drivers side blinker - it posts about 10V in an on-off pattern I'd expect. But neither of the two remaining holes do that if I flip on the passenger side blinker. Both blinkers work on vehicle (2000 Explorer XLT).

Shouldn't both blinkers post the same on-off voltage pattern or is there some funny relay thing that makes the right side blinker work or is my wiring just bad?

Any hints or direction would be greatly appreciated!

Thanks!