Ford Mustang Forum banner

07 mustang v6 BRAKE LIGHT OUT/ smart junction box

1K views 2 replies 3 participants last post by  bl817 
#1 ·
I replaced my brake lights but the most inner brake light on left and right side still won't turn on.
I dont know why it wont work.
I was reading reviews to possible check my smart junction box fuse that covers break lights. well when i open up the panel on the passenger side I heard this slight crackling noise. So i left it alone was wondering if anybody know what that noise was if its normal or how to fix the light

Thanks!
 
#2 ·
lift your passenger side floormat and see if the carpet is wet... if you havent cleaned your cowl drains, they are likely plugged with leaves and crap, the cowl fills with water, it spills in thru the cabin air filter, runs along the wire harness right to the SJB shorting it out... the other common SJB killer, is the a-pillar trim gasket... is it 'oozing out' around/above the rear view mirrors? if so, rainwater blows in there, runs right down the a-pillar and drips on the SJB... last common issue, if you have ever changed your cabn air filter, you probably noticed the little square plastic inserts in the top of the cowl, that the plastic snaps into...well, those inserts get loose and drip- right onto the SJB... yes these cars have some cowl issues.


I'd remove the SJB, dry it out, check for burnt pins, etc... mine was fine once dried out, but It was only wet for a day- the longer water sizzles stuff away, the faster permanent damage will occur. when I put mine back in, I put some 'gorilla tape' above it to act like a umbrella, and bent the wiring harness downward under the carpet sorta like a drip loop, so if cowl areas get wet again, will mostly get the carpet.

check the cabin air filter, it could be moldy and cause health issues too- on mine I clean the drains from under the hood- back under the ledge on the firewall, just behind valvecovers, are the rubber drains- they can pull right out easily to clean, but a little fun to pop back in... left mine out 2 yrs ago, they are self cleaning now...long as no exhaust leaks, should be ok- but might want to put them back in for safety reasons, just in case :)
 
#3 ·
IIRC the innermost light on each side takes a dual filament bulb but only comes on with headlights/running lights and not brakes. sounds like yours are working fine. however, if the lights are off and you have a random brake light on, especially after hard rain, then you would have water/corrosion on or in the sjb.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top