[94Spider]

Has anyone ever heard of the following scenario?

I have a '94 Spider and 10-20% of the time everythings great, the other 80-90% this is what happens:
1. WHEN HEADLIGHTS ARE OFF - turn signals work only when brakes are NOT being applied;as soon as brake lights are activated turn signal's don't flash. Brake lights work fine when headlights are off.
2. WHEN HEADLIGHTS ARE ON - turn signals don't work (brakes or not) and, when brakes are appled tail-lights turn off completely and only the high center brake light activates.

In either scenario there isn't any shorting or dimming of the lights - they either work fine or most of the time don't. When they are working it's for a stretch of time - like hours. The bulbs, fuses and relays seem to be in order. The car has never seen rain or snow so there doesn't seem to be any corrosion of electrical components anywhere - it only has 18,000 miles.

Any ideas would be greatly appreciated

Thanks!

Glen