Brake Light Issue…

Electrical issues, both 12 volt and 120 volt
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Colorado Coach
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Brake Light Issue…

Post by Colorado Coach »

A couple weeks back on my way to park the camper in storage, I noticed that the brake lights were out. Now I’m finally getting around to dealing with it.

After pulling the rear driver’s side taillight cover off and checking the bulbs (all good, filaments intact & showing resistance with a multimeter) I ran a few tests of what should be working back there. Here’s what I discovered:

-The taillights & rear blinkers are working perfectly.
-The brake lights, rear Hazards & reverse lights DO NOT work. (Front hazards work just fine.)
-Both filaments in the taillight bulb CAN light up. (Example: with headlights/taillights on, blinker works fine.)

An electrician buddy suggested that this sounds like an “Electronic” problem, not a wiring issue. Maybe some type of module is blown? Thoughts anyone?

Thanks in advance!
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skater
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B190 Year: 1991
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Re: Brake Light Issue…

Post by skater »

What year?

I'm wondering if you have two different problems. Maybe the brake light switch on your pedal is bad, and maybe the flasher is bad.

Also check they have a good ground but something tells me it's not that.

Another possibility is damage to the wiring harness somewhere. Not sure where to tell you to look for that, though.
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
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Re: Brake Light Issue…

Post by Colorado Coach »

Hey Skater, thanks for the reply. My Okanagan is an ‘88. I think the ground is working fine, as both filaments in the bulb are lighting up just fine (with the taillights and blinker) and I checked the socket for ground using the multimeter ohms setting, and I consistently got it to read.
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skater
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Re: Brake Light Issue…

Post by skater »

Your '88 probably doesn't have any sort of electronic modules that would be involved in this. I suspect a simple wiring issue, somewhere.
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
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Colorado Coach
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Re: Brake Light Issue…

Post by Colorado Coach »

So I checked the switch on the brake pedal with a multimeter. It seems to be functioning correctly. (Voltage from one of the wires all the time; voltage from the other wire only when I depress the pedal.)

I’m guessing this means it’s probably a wiring issue somewhere between the brake pedal switch and the bulb then?

I’m still not sure how the tail lights & turn signals are working though, but not the brake lights, hazards or reverse lights. Perhaps I’d understand it more fully if I saw a wiring diagram, but I’m more concerned about just getting it fixed than I am fully understanding it. Understanding it would be kinda’ fun though. :D
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skater
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Re: Brake Light Issue…

Post by skater »

Colorado Coach wrote:
Tue Jun 21, 2022 1:26 pm
So I checked the switch on the brake pedal with a multimeter. It seems to be functioning correctly. (Voltage from one of the wires all the time; voltage from the other wire only when I depress the pedal.)

I’m guessing this means it’s probably a wiring issue somewhere between the brake pedal switch and the bulb then?

I’m still not sure how the tail lights & turn signals are working though, but not the brake lights, hazards or reverse lights. Perhaps I’d understand it more fully if I saw a wiring diagram, but I’m more concerned about just getting it fixed than I am fully understanding it. Understanding it would be kinda’ fun though. :D
Yeah, it's really strange. I have the electrical book for my '91, and yours is probably the same, I'll take a look when I have a moment to see if anything pops out at me. It's especially weird since the turn signals and brakes use the same filament, I think.

This is a new problem, right? I.e., they all did work at some point while you've owned the van?
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
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Colorado Coach
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Re: Brake Light Issue…

Post by Colorado Coach »

Yep. Definitely a new problem. Thanks Skater!
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Re: Brake Light Issue…

Post by Colorado Coach »

Turns out…it was the turn signal switch! I guess the brake lights run through that switch? Weird that the rear blinkers worked just fine if the switch was faulty.

As far as the reverse lights go, the mechanic said he never saw a problem with them. My guess is my 9-year-old “helper” I had standing behind the van when I tested them was feeding me some incorrect intel. :roll:

Thanks for all your help Skater! I’m now waist-deep in painting Okie’s interior. Hopefully she’ll be ready to do some camping for the 4th!
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skater
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Re: Brake Light Issue…

Post by skater »

Colorado Coach wrote:
Sun Jun 26, 2022 12:07 pm
Turns out…it was the turn signal switch! I guess the brake lights run through that switch? Weird that the rear blinkers worked just fine if the switch was faulty.
Glad you figured it out! I forgot to check the wiring diagrams for you. :(
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
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