C4 High Brake Light

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Mar 15, 2021 | 12:07 PM

ellis1969

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Joined: Feb 2015

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From: SC

C4 High Brake Light

The high brake light on my C4 '89 convertible occasionally illuminates when the car is engine-off in the garage. Once, even resulted in a dead battery.. If I "wiggle" the brake pedal, it usually turns off. Could there be a second switch form the brake lights? Other brake light functions are as expected.

Mar 15, 2021 | 04:24 PM

c.w.moss

Instructor

Joined: Aug 2004

Posts: 203

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From: Caldwell Texas

Seems to me the brake light switch is adjusted to tight to the pedal. Back it off a turn and see what happens. What gets me is that only the 3rd light is the only one coming on, I would think all the brake lights would shine.

Last edited by c.w.moss; Mar 15, 2021 at 04:26 PM.

Mar 15, 2021 | 04:38 PM

rblakeney

Racer

Joined: Apr 2017

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From: Katy Texas

There is indeed a second set of contacts in the brake light switch for the center high mounted light. My 89's center light (coupe) would not come on and I removed the switch. Opened it gently and cleaned out the contacts. They were gummed up but otherwise looked healthy.

Mar 16, 2021 | 08:42 AM

ellis1969

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From: SC

Excellent information. Thank you both. Last year, I removed the entire steering column for rebuild. May have "moved" it a bit then.

Mar 16, 2021 | 11:16 AM

JoBy

Melting Slicks

Joined: Mar 2001

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From: Timra, Sweden

It is separate switches because of combined brake light and turn signals.

Mar 16, 2021 | 11:45 AM

WVZR-1

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You need to concern yourself with only the SLS that has the LTBLU wire to it. LTBLU is the signal for CHMSL & also ABS etc. 8A-110- for FSM reference - all years w/CHMSL

Mar 16, 2021 | 12:03 PM

ellis1969

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From: SC

Thanks, JoBy and WVZR-1. Since I am not a small person, just wanted such info before wriggling under the dash.

Mar 16, 2021 | 12:21 PM

WVZR-1

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Quote:

Originally Posted by ellis1969

Thanks, JoBy and WVZR-1. Since I am not a small person, just wanted such info before wriggling under the dash.

I'd suggest you establish a plan 'after' a first visual and attempt to 'reseat' the SLS in the retainers. You mention 'wiggle' of brake pedal in the past. Reseat might accomplish your needs. Might not! If you can record #'s from your SLS(s) on the 'first dive' it would be suggested and maybe a snapshot or two.