TreyH

Hey all,

I've got a 2005 v6 mustang and am having a weird problem. Unless I turn on my headlights, none of the rear lights work. And when I do, the signal lights still don't work. Does anybody out there know what could possibly be wrong and what I need to do to fix it? Thanks.

Nuke

Try using the wiring diagrams to help with your troubleshooting.
http://iihs.net/fsm/?dir=1

From your description it almost sounds like an issue with the light switch but I haven't looked at the wiring diagram.

7gtthrilla

You could have a short fuse or one in the wrong place. Check your wiring first then go with what Nuke said.

flattrack

Make sure you trace out the harnesses and make sure the grounds are attached properly.

obxdude018

Have you ruled out the infamous water leak our '05 suffer from, look a the junction box by the passenger floor for water and behind the box as well