I had some bulbs go out in the tail lights of my 2007 V6 Classic so I bought 4057 Bulbs and replaced them. All seemed to work fine except the innermost light on both sides. It comes on when I turn my headlights on but it won't come on when I press the breaks. The outer two on both sides are completely fine and light up with turn signals, emergency lights, and brakes. My problem is those two middle lights that are right above the reverse lights. If anyone has a suggestion as to what I should do please post and be as detailed as possible. I'm learning so keep it as simple as you can. Thanks

 

Sounds like the car is fine, those "inner" or 3rd strip of light bars are not supposed to light up during braking. Only the 2 outer most on each side will brighten for the brake sequence, although all 3 on each side will illuminate for parking/night driving lights.

Hope I didn't confuse you, just let us know if you need any further clarification.

If you really want them to light up you could always get a sequential taillight harness. Beauty of the mustang is that anything you want, you can add due to our HUGE aftermarket and customization capacity.

Enjoy the car! And welcome to the forum.

 

Okay then! LOL! I thought for some reason they were all supposed to light up... Thank you very much for the information and for welcoming me to the forum!

 

The are suppost to illuminate with sequential taillights...
Not OEM.
The center most bulbs are not 4057 bulbs but 4157 instead.
Actually 3057 and 3157 is what the owners manual calls for.
The increased load of the 4057s might damage the SJB.

 

Interesting. My owners manual state 3057K or 4057K for the tail lights regardless of position.

Also try to find bulbs that have LL in the part number. That is for long lasting and they really to last much longer then the stock bulbs.

 

+1
Sylvania LongLifes rule!!

 

FYI: The 2005, 2006, 2007, 2008 and 2009 owners manuals I have all show 3057K or 4057K for taillights. Not sure why yours would be different.

 

Is this true? I've seen some forum posts besides this one indicate it is but can someone point me to official documentation to support this? My son was just refused to take his driver's test in the Mustang because the inner lights did not light up. I showed them they did if car's headlights were on and pointed out it had passed state inspection just two weeks ago. They insisted they should come on without the headlights and said the car still has to pass THEIR inspection. It would really be nice to show them documentation that it's NOT broken.

 

What year is the Mustang? 2005 - 2010 only the two outside bars light up with brakes. It should be in the owner manual

 

'05. I skimmed a PDF of the owners manual with Ctl F and couldn't find it. Maybe I'm using the wrong words. I'll look again.