Two problems related to headlights have been reported for the 2005 Ford Mustang. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Ford Mustang based on all problems reported for the 2005 Mustang.
There is an apparent design flaw in 2005 Mustangs as I have read hundreds of similar complaints as to what I am experiencing. Due to this design flaw after a recent day of heavy rain 1 headlight and 1 signal light will not turn off once the car has been shut off. I researched and apparently the Smart junction box (sjb) got wet and the electrical unit is now malfunctioning. There was also a strong burning smell when I got home that night as well. Spoke with an online mechanic technician and he confirmed that the sjb needs to be replaced. There has been a long history of the car leaking on the passenger side whenever it rains due to the design flaw. Also my gas gauge never reads properly, inside lights are also dim/off and the check engine light has been going on and off for nearly a year and my mechanic could not diagnose why the reviews online said when they spoke to Ford that admitted that it was a known problem but because there has been no recall that they will not repair this for free. Estimates I read put the cost around $1000 to get this fixed and do not want to pay that kind of money especially when Ford admits to knowing there is a problem. I am hopeful that we can get Ford to do the right thing and issue a recall for this. It is a serious problem since the electrical system can cause a fire from reports I have read. This happened to meet on 12/21/18. I was driving home from work and parked the car and shut it off. As I locked the car I noticed that the drivers side headlight and passenger side signal light stayed on and I had to disconnect the battery to make them shut off. Also there was a strong burning odor when I lifted the hood.
Water got to fuse box made headlights go off and flooded passenger side of car.