These install instructions would of helped.
https://www.taillightking.com/images/Turn%20Signal%20Switch/5007R-diagram.pdfhttps://www.taillightking.com/images/Turn%20Signal%20Switch/TurnSignalSwitchWiring.gifO.P. wrote
I found a short in the wiring harness between the tail light wire and the left turn signal wire.
Sounds like the trouble was more like crossed wires. A trouble that would not cause a fuse to blow.
I wonder if the trouble only occurred when the headlight switch was in the ON position ?
A "short" could mean different types of troubles.
A short to ground or a short circuit.
A short circuit is simply a low resistance connection between the two conductors supplying electrical power to any circuit.
A short to ground is when the positive is touching the negative.
Then there is a swinging short, as when the wind blows and swings the telephone aerial drop causing the two conductors (Tip + & Ring-)
to short circuit ON & OFF arcing. Fooling the telephone central office switch into thinking someone is dialing 911.
Electricity is some funny stuff..
