I just bought 4 hella 500ff's and i mounged them on the roof, i had them working the other day when i put them on then i went to turn them on last night and they didnt work, i checked all the connections, replaced all the fuses and still got nothing, i know i have a good ground casue its the same one i was using when they worked, i dont know what else there is that it could be, the lights came with a relay, im not sure if thats the problem yet or not, i wanted to see if there was anything else

 

are you useing 2 relays or 1? You need to use 1 relay per set.