Brake lights stuck on?

BLISSFULBEAUTY1983

MEMBER
2004 FORD EXPEDITION
5.4L
V8
4WD
AUTOMATIC
225,000 MILES

Vehicle turned to on position, all lights work fine. When I start vehicle, key in run position, brakes illuminate and stay on the whole time. But I turn suv off put key in "on" position and there no problem with any of my lights and work as they should. I've changed bulbs, sockets, brake switch and flasher so far.

Wednesday, December 3rd, 2025 AT 4:45 PM

2 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

Hmm, that make zero sense since the brake light circuit is "live" at all times, so the light should be on at all times but you say they go off with the key off correct? There is no controller or relay in the this system there is only the bake light switch, can I ask if the vehicle has a aftermarket alarm system, if so I would remove it because this can cause the issue, or someone has messed with the wiring. Please give me more information so I can help you.

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Thursday, December 4th, 2025 AT 8:53 AM

STEVE W.

MECHANIC
15,231 POSTS

Are the bulbs conventional halogen or have they been replaced with LED? When they are on, do the front turn signals also come on or are they off? What happens if you start the truck let the lights come on and pull up on the brake pedal? Do they go off? If you turn on the marker lights do the brake lights come on or is it only with the engine running? Was this a former police/fire vehicle? Does it have a tow hitch?

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Thursday, December 4th, 2025 AT 9:28 AM