D was the one that melted(blew) not E??
D goes to main light switch and cab fuse panel, here:
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Headlights_1983to1989.JPG
It could run all the way back to the battery, starter relay, but then AMP meter wouldn't show its power draw.
Fusible Links are fairly short wires, 6 to 8 inches, if fusible link is a 16gauge wire then you should use a 14gauge wire with it, so always 2 gauges larger, 1 is OK, 2 is better, with a short the 16gauge wire can do its job, melt and separate, and 14 gauge would just get warm, if you used the same size/gauge, or smaller then whole wire would melt
AMP meter passing full amps thru it would be impractical and dangerous in a vehicle
So what is done is to install an AMP shunt.
It is basically a large resistor that connects the battery to the vehicle power systems.
So fusible link C goes from battery(starter relay) to AMP Shunt, links D and E connect to other side of Shunt, they power the cab electrics, engine electrics(via ignition switch) and headlights
The amp meter hooks to battery side and power draw side of Shunt.
The meter and shunt used are calibrated, made to work with each other, so amp meter can be showing 25amps, but only .25amps are actually passing thru the amp meter, shunt and meter are calbrated to 100 to 1 for that example.
99% of amps go thru Shunt, 1% thru AMP meter, way safer
Battery---starter relay------(link C)--------Shunt-------(links D and E)---------->>
All power is passing thru link C, like 50 or 60amp fuse used in later years, but they switched to Volt meter, so could run head lights and Blower thru separate fuses because no AMP meter was used
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