Review on Bussmann FMX 40 MAXI Fuse Female by Joseph Stone

If you have a half-ton Chevy/GMC truck with a 7-pin trailer connector, you may find that the 12-volt pin in the 1 o'clock position does not match power is supplied. You will find a dummy fuse in the fuse box under the hood. This fuse replaces that fuse and now powers that 12 volt pin going back to your trailer. Particularly useful for RVs to power 12V devices. Without this fuse, the plug will only power the trailer lights and trailer brakes.