I've used my trailer lights in the past no problem but last yr we pulled my 4 x 8 and no lights worked. Later I used my 6 x 12 and they didn't work either when they used too. Today I checked the fittings underneath the trucks rearend, the interior fuses and the underhood fuses and all are ok. I found no rusted fittings, no blown fuses and no loose grounds but dang if I can figure this out. These stopped working probably one yr ago but rarely pull so I just forgot about them. Tuesday I'm going out of town pulling a trailer and REALLY need these lights. Any suggestions????