How to fix my backlights

Did you replace them with new ones or used ones? The tailight assemblies on these cars are notorious for leaking due to the seal between the lense and the housing failing. They are virtually impossible to seal up again without making a huge mess. I speak from experience. I would suggest taking the light assemblies out again and drilling a couple of good sized drain holes in the bottoms to let the water out. It won't stop them from leaking, but the water will simply pass through and not collect inside. It's getting to be a pretty old car so even though the "fix" is a bit crude it should do the trick for the balance of the car's life.