Nice work. You have provided a good description of the situation and I fully understand the problem but there are 3 different systems used for the headlights so I need to clarify which is the correct one.
1. Headlight circuit with Daytime Running Lights (DRL)
2. Headlight circuit without DRL & with Auto-off headlamps
3. Headlight circuit w/o DRL & w/o Auto-off headlamps
Attached are the diagrams for the taillight circuit and please note that you are only to concentrate on the ones designated for EX and not others.
The taillight system is working correctly but somewhere the headlight switch is interfering and providing a direct ground for the taillight fuse ( # 10 in passenger fuse block) when the headlights are turned on so the headlight circuits would provide abetter understanding of what could cause it.
In the meanwhile, unplug the taillight relay and test if the fuse blows. This would allow us to understand if the shorting is before or after the relay.
Images (Click to enlarge)
Friday, February 15th, 2013 AT 5:58 AM