XJRider.com

I've ran through everything I could, for some reason my rear running light(tail light) is not working. My break light(same bulb, different filament) is fine. I've pulled out the taillight assembly, I've tried 3 different(and new) bulbs. The kicker is the fact my multimeter is showing 10.5 volts on the contact(while not running)...but when I place a bulb in it the bulb doesn't light. I've tried wrapping wire to the contacts and running that straight to the bulb to see if maybe the housing is shorting when the bulb is in but I'm still not seeing anything.
Any ideas of what may be the issue?
Thanks in advance
The bike is a 1992 XJ600