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  1. #1

    Default Tail & Brake Light Problem ~ 2003 Chevy Trailblazer

    This is my first post. I was referred to this site by a member at the Trailvoy forum. I have a 2003 trailblazer w 184,000 miles. Recently the Break/tail light will just come on. This morning I took the dogs out. the tail lights were off. Got into the yard, saw a red glow, turned around and the tail lights were on. I got in, pressed the break peddle. When I stepped back out of the truck, the break/tail light was off. Could it be Break peddle sensor or a fuse? I tried searching the forum but did not find anything

  2. #2


    That's a new one for me. You came outsite to a cold Trailblazer and the lights were off, then at some point with no one having access, the lights were on?

    I think at one point the sunshine hit the lights in my Trailblazer to a point where I thought they were on, but they were being illuminated by the sunlight instead of the internal lamp. Do you think that's a possibility?

    Also, maybe someone hit the lock / unlock button on the Key FOB and it either locked or unlocked and that caused the lights to be on? I've had a child before do this and even once set off the panic alarm at bedtime when he snuck the keys into his room.

    10 Chevy Traverse LT AWD
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  3. #3


    no one near the car. It has been happening the past couple of days so I have been making a point to look at the tail lights every time I walk by the truck. Today, 5:30 am(no sun light), while walking the dogs, I looked at the tail lights, not on. 30 secs later, I looked back at the tail lights and they were on. No one else was awake. Key fob was on a shelf in the house. The head lights were not on, Just the tail lights. If the panic button was hit, the horn would go. Doesn't the head lights come on when the unlock or lock button is hit?

  4. #4


    Yes your GM day running lights should have come on if someone hit the key FOB. That's some freaky stuff man. You don't live by a cemetery do you? JK

    Have you checked the connection where the bulbs themselves plug in? I know dirt/corrosion can cause them NOT to come on (experience), maybe it could have the reverse effect?
    Hotty Toddy!

  5. #5


    I think it is the brake lights (and not the running lights) that your seeing. Your battery must be in good shape.

    I suspect you need to replace the brake light switch; or, you might be lucky and be able to adjust it.

    The switch is on the pedal arm and, I think the adjustment is above the switch (you'll have to crawl under the dash and check). The adjuster should have a threaded shaft that will let you shorten, or lengthen the shaft.

    Remove the trim panel, at the bottom of the dash, to give yourself a bit of room.

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

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  7. #6


    Each time you saw the lights on...was it wet outside? Either due to rainfall or dew?
    2004 Chevrolet Avalanche Z66 WBH, AVS smoked rain guards, AVS smoked bug shield, Bose 6-disk CD changer, Bully Fire Strip w/ Sequential turn, 6 on-high, amber DRLs, tinted euro tails, Pace Setter Performance Dual Exhaust, K&N CAI, GlowShift gauges in dual pillar pod.

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