Both of my front turn signal lights always had water in them then it would try to evaporate and fog the inside of the lens. I took them inside overnight to dry out and used some PVC conduit cement made by Rectorseal. I put two applications of the stuff around the lens seam and let it dry overnight. Stuff smells like hell, have good air flow when using. After 1500 miles, car wash and driving rain, no more water! Just thought I'd share.