Hmm. Inside turn signal indicators function differently with headlights on

[jocko]

Added a tach so had to remove the instrument cluster and replace the printed circuit. Other than that, no changes, just remove and reinstall, have done this many times on several trucks.
So... now that it's all back together, turn signals work great with the lights off (all outside turn signals and all inside turn signal indicators). With the headlights on, however, selecting left turn signal results in a right blinker indication on the dash (but all the external turn signals blink as the should based on the position of the turn signal lever). Opposite happens when right turn signal selected (inside blinks on the left, and outside are all indicating as they should be). So, it's safe to drive, since what I select on the turn signal indicator is what actually happens on the outside, regardless of headlights on or off. It's only when headlight are on that the inside (only) indicators indicate backwards. Can't just be something simply like wires in the wrong place - it's a printed circuit board, only one way to go on.

I "thought" it might be the fact that the printed circuit was kinda scrunched because of a ground connection on the circuit board that wasn't quite where it needed to be, so removed it and smoothed the cb out, made no difference though. And one time, it just started working... shut the truck down, and then when started up again, it was back to the inside turn signal indicators blinking the opposite side when the headlight switch was on.

Anyone ever seen this before? Getting kinda tired of taking this silly thing in and out, thought I'd see if anyone has any ideas.