why the diode
 

been going through the electrics with power on since i did some wiring work just to make sure everything worked and nothing was going to melt. with porsche wires, you move them around too much and its trouble.
anyway, my right side lights were not working. they would come on with the key off and the turn signal to the right for the park lights, but nothing with the headlights.
so i found it was the diode coming off the headlight switch for the right side. thing is, there is only one for the right and not for the left. i looked over that circuit front to back and for the life of me i cant figure out why it is on the right side and not on both. if the diode was bad i was thinking good luck trying to find a new. but it checked good and when i put it back in the lights worked. so perhaps a bad connection.
still, why is it there? the ONLY thing i saw different between the left and right was the right also pwered the the lisc plate light.

BTW, if you dont know, the grounds for the tail lights is on the upper bolt for the bumper. you can get to it by pulling the tail light.

the more i dig into porsche wiring the less i like it. they put fuses AFTER switches. thats too much wire to not be protected by a fuse. i also find wires that are bent at sharp 90 degree angles instead of having radius to them. it weakens the insulation which can make it break.

That maybe it has to do with the historical fact, that electrons in metal flow from minus to plus (physical direction), only in shematics from plus to minus (technical direction), so this makes sense in my eyes as the current reach the fuse before the switch in real world.

On the other side, a lot of fuses are on the plus side, that's for different reasons:

-Easier for fault evaluation

-Earth faults are fused too

-no tension on electrical user when working at and fuse is out/blown -> safer for mechanic

PS. This is only valid for DC, not AC

you made me think for a moment, ouch.
fuses protect wiring. all that wire that runs up to the light switch, then the hi/lo switch and maybe the hazard sw then back to the fuse panel. that is a big potential for a short.
all it takes is for one of those wires to short out to the body or a ground wire in a bundle then its full power of the battery until the wire breaks. but, put a fuse closer to the battery and the current is limited by the fuse...hopefully.
my wiring is in really good shape but i still find wires with cracks.