For all 1969 to 1973 Mustangs, there's a capability to add an extra fused accessory (ACC) plug on the diagonal spot on the fuse box. I've gotten a fair number of requests to add this fuse buss/extender, but they are fairly rare to find. The part is C8OB-14A033C, along with a 34653-S36 nut/washer assembly. The wire extender is C9ZB-14A318A. The extender is designed for a 20 amp fuse.
I have built a prototype assembly and wire extender capable of 30 amps, using the basic components that Ford used. The only differences between my prototype (and ultimately the final product) and Ford's is the lack of iridescent chromate plating.
I cannot make very many of these, as the three-prong plug is harvested from various harnesses, and there are only one year that has wiring that can carry 20 amps. If anyone is interested, contact me via PM and I'll provide pricing, which is very reasonable.
The original fuse buss is on the left; my prototype is on the right.
