Turn Signal Woes

[ILikeMy240sx]

This is not related to a Nissan car but I have a '91 Honda Accord with a turn signal problem that I hope you can help me with.

My rear left turn signal is not working. All the other signals are working including the front left turn signal.

1. I have replaced the bulb with the one that I know works.2. I have checked all the fuses to make sure they are good and they are.3. I know the socket it self is good because I cut the socket from the wires and connected it directly to a 12v source and it lit up.4. The ground is good as I have continuity between the ground wire and a known good ground.

Here is the weird thing... When I pull the bulb out of its socket and measure the voltage, I do get fluctuations in the voltage just like it should. However, as soon as the bulb is plugged in I get 0 volts. Why is it that I get a voltage reading with no bulb but zero voltage reading with the bulb in? Perhaps the current flowing through it way too low? If so, how?

Any ideas on what could be the problem?