I had the same issues and even kept blowing fuses in my truck. I have my boat out year round. Fishing spring/summer and duck hunting fall/winter. Hot incandescent bulbs + really cold water usually equals a blown bulb. Forgetting to unplug usually led to a blown fuse. After replacing several bulbs, fuses and light housings due to corrosion I finally bit the bullet and got a complete set of LEDs (tail and marker lights). I also completely rewired my trailer and ran my ground wire from the harness back to both taillights. Did this about 3 months ago and haven't had any problems since. I no longer unplug before backing down the ramp and the LEDs are MUCH brighter, which makes me feel better when running to the ramp in the dark. Wish I would have made the LED conversion a long time ago!!