Headlights turn on when braking. Wah?!?
08-02-2007, 04:24 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Headlights turn on when braking. Wah?!?
My head lights turn on when i hit the brakes. I have traced both earths that i could find and they check out ok. What should i be checking?
Also, where online can i get the tiny rear spoiler light bulbs with the two prongs?
Thanks!
Also, where online can i get the tiny rear spoiler light bulbs with the two prongs?
Thanks!
08-02-2007, 01:59 PM
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Re: Headlights turn on when braking. Wah?!?
If you already checked the grounds and they are ok, you will need to start eliminating different pieces of the puzzle.
1) Turn on headlights. Does the hi/lo beam switch work right? Are the brakes lit?
2) Turn off headlights. Hit the brake. Which headlight is on? Driver, passenger, lo-beam, hi-beam? Does the hi/lo beam switch work right at this point?
2) Pull one taillight and one brakelight socket and bulb. Measure voltage on the outside of the socket (which should be grounded) with brakes applied. If you see any voltage, it's a bad ground.
3) Hit the brake. Measure voltage on the headlight (do not disconnect it). Do you see full 12V?
Lou
1) Turn on headlights. Does the hi/lo beam switch work right? Are the brakes lit?
2) Turn off headlights. Hit the brake. Which headlight is on? Driver, passenger, lo-beam, hi-beam? Does the hi/lo beam switch work right at this point?
2) Pull one taillight and one brakelight socket and bulb. Measure voltage on the outside of the socket (which should be grounded) with brakes applied. If you see any voltage, it's a bad ground.
3) Hit the brake. Measure voltage on the headlight (do not disconnect it). Do you see full 12V?
Lou
08-03-2007, 03:22 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Re: Headlights turn on when braking. Wah?!?
Great, thanks for the awesome insight. I'll ckeck all that stuff. My headlight switch seems to have been rewired, as the first indent on the pull-on headlight switch turns on the full headlights, and they stay on when you pull it fully out...
Thanks Lou
Thanks Lou
08-03-2007, 03:34 AM
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Car: '91 RS
Engine: 5.0L gross *** tbi
Transmission: 700r4
Axle/Gears: 2.73
Re: Headlights turn on when braking. Wah?!?
hehe sounds like you look funny in a rear view stopping at a light 
08-03-2007, 09:21 AM
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Re: Headlights turn on when braking. Wah?!?
Normally, the brake circuit and headlight circuit have nothing in common (besides the juice coming from the same battery). A single fault in either system won't cause the condition you're seeing, there are multiple problems at play. A faulty/rewired headlight switch would be one of the multiple problems.
Let us know what you find out. I'm very curious. I love electrical puzzles.
Lou
Let us know what you find out. I'm very curious. I love electrical puzzles.
Lou
08-03-2007, 12:31 PM
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Car: 1986 Vert Z28
Engine: SuperCharged 350
Transmission: 5 Speed Manual
Re: Headlights turn on when braking. Wah?!?
I'm wondering, does it happen absolutely consistently? Like, if your in park, and you hit your brakes does it still happen?
I had some weird issue like that way back in the day, and it ended up being a stripped wire grounding out when i hit the brake cuz the car would slightly lurch forward enough.
*shrug*
I had some weird issue like that way back in the day, and it ended up being a stripped wire grounding out when i hit the brake cuz the car would slightly lurch forward enough.
*shrug*
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08-04-2007, 02:57 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Re: Headlights turn on when braking. Wah?!?
I'm wondering, does it happen absolutely consistently? Like, if your in park, and you hit your brakes does it still happen?
I had some weird issue like that way back in the day, and it ended up being a stripped wire grounding out when i hit the brake cuz the car would slightly lurch forward enough.
*shrug*
I had some weird issue like that way back in the day, and it ended up being a stripped wire grounding out when i hit the brake cuz the car would slightly lurch forward enough.
*shrug*
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