1st just no tail lights, ohmed out #6 fuse and both bulbs, all good. Went to forums, did everything they said to no avail. Then discovered all worked using light switch manually instead of auto position . 20 minutes later only only left and upper brake light if you turn the switch manually. Anyone?

 

Year and model would be helpful.

 

It's a 2000 jeep grand Cherokee limited

 

I drive a '00 WJ base model that doesn't have an auto feature light switch. I wonder if it's your switch, especially because they all worked for a short time. I once looked at the circuit diagram for the rear lighting and there are so many connectors in the circuit, I wouldn't begin to know where to start looking for a fault.