I think the point that Graham made earlier was that any brown wires (in his photo just 2 but in your case 4) emanating from the starter solenoid need to be protected by a suitable fuse before they reach their own respective fuses. If those brown wires should short to earth the battery will feed an enormous quantity of energy in prior to exploding or the wires burning out!
The problem is Doug where do you draw the line. Adding fuses in series with existing fuses not only causes minor volt drops dependant on current flowing through them, but far worse it adds unreliability, connections loosening etc. The fuse is there to protect the equipment it's feeding and the cable to it. Better though that effort is put into good mechanical installation with the heavier gauge cables leading to the fuse box in a clean dry location as with normal automotive practice.
There is a case on a long cable run where current can flow either way, being fused at each end but I can't think of a situation on a car that would qualify for such.
