9004,9007 Wire Harness-Double Fuse Boxes 1. double relays and double fuse boxes 2. ISO9001:2008 3. easy installation Advantages:1. More ... Safety: double relays and double fuse boxes, if one of your lights has something wrong, the other ... , Welding, Assembly and Testing. 9004,9007 Wire Harness-Double Fuse Boxes