you dont need to know what fuse is for what to know thats its has blowing,,if you know were the fuse box is on the ford cargo "the fuses will be different colors for different jobs, and the all are of the same shape, two prongs comming out of them ,if you take one out and look at it, you will see a U shape wire going between the two prongs. if the U shape wire is broken then that fuse has blowing" so all you do is find the fuse box , take out one fuse at a time, check for the U wire ok, put that fuse (back,) and go on to the next one,and do the same till you find the blowing one , but before you put the new one in , check the wireing in the lights to make sure that its tight, this could also be your problem ,wires in the light not makeing good contact, check that first,before the fuse box, the light may be on a 10 or 15 amp fuse, it will have the amps printed on the fuse, check them first, oh and make sure that the engine of off and you have the keys when working on the truck.. good luck
m, March 2011