I had the same problem with my 77 Caravanner, I took the lens off and checked the power and had full power, still was dim, so I took the lens off my car and compaired them, they were the same brightness with just the bulb hangin out,still didnt have that warm and fuzzy feeling,so I painted the inside of the bulb holder white,still not the best results,,,,,,,, so I went to Carquest and bought LEDs for boat trailers for $49.00 did some fancy fileing and they look awesome!!!! its the only way to go , total of $100.00 and I feel so much better about putting on the brakes,