the tail light (brake light) on my 2000 996 convertible is very dim and when I turn the headlights on it goes out. I tried the bulb from the other tail light and got the same results. whats the next step to consider in trouble shooting this?

 

That's an odd one. The first thing I would do is to clean the contacts and look for frayed wires.

 

contacts have been cleaned with a tiny wire brush, blown out and treated with a conductive paste. no frayed wires can be seen anywhere

 

Check the voltage at the socket while having someone turn the headlights on and off.