I had that problem with only one though after I put my BL on. One of my wires got cut somehow. I just soddered it back together. I can't spell that word, but I hope you know what I'm trying to say haha. Look for any split wires?
If you have aftermarket bulbs, (like blue or white or something) sometimes the watts don't match up. and it happened to me too. I just had to order the new wiring harness off ebay cuz the wattage of the new bulbs was too much for the stock wiring. Cheap and easy to fix
either that or its the wiring harness' and you bought bulbs with wattage that was too high for the stock wiring harness'. Also if you touched your fingers on the bulb itself when installing, sometimes it shorts them, most of the times actually