Tag light brake light not working properly

2008 FORD TAURUS
233,000 MILES • 3.2L • 6 CYL • 4WD • AUTOMATIC
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LEOLEO8
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When I start my car listed above (Excel) I didn't turn on my headlights and I have no running brake lights or tag light.
Jan 2, 2021 at 3:14 PM
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KASEKENNY
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More then likely this is the smart junction box has failed but we need to test voltage coming out of it when the lights are supposed to be on. I am attaching the wiring diagram and here is a guide that will help with doing this testing:

https://youtu.be/Hlna_kUt7As

The SJB is more then a fuse block as it has a microprocessor on it and they are pretty common to cause issues like this.

Let us know what you find with this and we can go from there.
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Jan 6, 2021 at 4:06 PM