Might be a ground problem (given that it's direction specific) or the relay. For me, both turn signals (and emergency flashers) would go solid after flashing for about half a minute. Replaced the relay and solved that particular problem.

In your case I'd start by checking the grounds on your left hand signals.

-Jarrett
On Feb 15, 2013, at 9:43 AM, Craig Cowan wrote:

> So i've got an odd intermittent issue that i've never dealt with before.
> My blinker ALWAYS works right when blinking to indicate a "right" turn.
> About 60% of the time Left blinker works properly as well.
> But, sometimes i'll indicate a left and the green LED will just go solid,
> and the blinkers don't blink.
> Shutting it off and turning it back on a few times can make it blink
> normally  though.
> 
> I thought they blinked fast when the bulb was out, so what's this?
> It's a '90 GL auto with cruise.
> 
> -Craig