XC90 Turn Signal_2007_Wiring.JPG Try fuse #2, see what that does. Wire color code for left turn signal is Green for 12V, Black for ground. Wire color for right turn signal is Green/White Stripe for 12V, Black for ground. If fronts signals are working, then your switch is working. EDIT- Had wrong is...

It's actually a good thing, now you know where to look. Driver side door has a known issue whereby the wires can get worn out and fray. That it's a driver side issue with driver side door position making a difference is perhaps indicative of a worn wire or partially mechanically compromised conducto...

Was thinking about this while you checked, the green/white wire is easy enough to resolve since it's the same conductor. It's the ground that's going to be a little more problematic. You could dump a bunch of solder in the area and hope for the best, but that spot is always going to be a flex point ...