Racing Fuse Box with 12 Pre-Wired Relay Circuits | MGI A specialized 12 circuit fuse box designed for racing and professionals. Featuring 12 smart glow fuses, 11 load circuits, and 3 integral relays, this 12vDc racing fuse box is designed for high-current, relay controlled race car accessories. All load circuits are conveniently designed to be wired to relays. 12 circuit fuse block | eBay Find great deals on eBay for 12 circuit fuse block. Shop with confidence. Skip to main content. eBay Logo: Shop by category. 8 product ratings - 12 Way 24 Fuse Box Circuit Standard Blade Block Holder Car Boat DC 12V-32V US. $21. Save up to 6% when you buy more. Buy It Now. Free Shipping.