Hmmm,
From what I've been reading on search threads and this one, most of the fixes have involved replacing the turn signal relay or tracking down poor grounds, as if they may start to signal correctly, but as soon as the bad ground is hit the turn signals are suddenly taken out of parallel and put into series, thus dividing the voltage (and thus the intensity) to each...and they both wind up illuminating. Slicker 'n snot...
Ryan