Electrical short - let this be a lesson - never assume

[ktm]

Yesterday while driving to the Irvine Cars and Coffee, my dashlights, running lights and headlights all went out right as I arrived at the location.  I had them on for 35 minutes without any issue.  Upon arrival at my destination, I suddenly noticed that my dashlights were out and when I tested my headlights, I could see that they too were now non-operational.

 

I thought I had simply blown a fuse, but it kept blowing as soon as I replaced it.  Damn, an electrical short.....

 

I spent 2.5 hours today chasing the short.  I rewired most of my car 4 years ago due to an electrical short that started a fire in the engine bay.  I *knew* it could not be my wiring but I tested everything just to be safe.  Sure enough, I narrowed it down to the rear tail light/running light harness which I did not rewire.  However, that was not the culprit as it turned out.

 

I had everything in the rear disconnected except one wire......one wire that should have been connected to ground.  You see where I am going.  I had the car painted in February and the painter removed the marker lights to paint the car.  Well, long story short, he switched the wires on the passenger side marker light.  I have no idea why the light functioned for 30 minutes before finally blowing the fuse, but when I was chasing the short I went through a number of fuses because I assumed that that lone wire I did not disconnect was connected correctly.

 

I examined it closely and realized that the power wire from the harness was connected to the ground wire on the light.  As soon as I disconnected it, no more blowing fuses.

 

I post this as an example to never assume.