1981 SC brake lights failure
10-05-2003, 12:23 PM
#1
5th Gear
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1981 SC brake lights failure
My brake lights fail to come on when the pedal is depressed. Fuses check out fine. Bulbs are fine. My brake light warning light (on the dash) came on also. I reset the light by disconnecting the battery ground strap. Also my cruise control fails to come on...Not Sure if all of these things are related. Not sure how to check the brake light switches on the master cyclinder either.
Any thoughts?
Michael Irwin
1985 928S (Red)
1981 911 SC Targa (GULF Orange)
1973 914 2.3L (4cyl.) (Hot Lime Green)
Any thoughts?
Michael Irwin
1985 928S (Red)
1981 911 SC Targa (GULF Orange)
1973 914 2.3L (4cyl.) (Hot Lime Green)
10-05-2003, 12:31 PM
#2
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Hi,
I vaguely remember the cruise control system disables itself if there is a fault with the brake light switch. Could you disconnect the 2 wires going to the brake light switch and touch them together? I guess if the brake light then comes on, most likely the switch is faulty. Furthermore I think you can test it by an ohmmeter. There should be some resistance when the switch is on.
Good luck
I vaguely remember the cruise control system disables itself if there is a fault with the brake light switch. Could you disconnect the 2 wires going to the brake light switch and touch them together? I guess if the brake light then comes on, most likely the switch is faulty. Furthermore I think you can test it by an ohmmeter. There should be some resistance when the switch is on.
Good luck
10-05-2003, 12:39 PM
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911 SC brake light failure
!981 911 doesnt use the brake light switch at the pedal. It uses the 2 switches attached to the master cylinder.I could by pass the switch to see if the lights are on.
10-05-2003, 01:54 PM
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SC brake light switches
Was told there is a matching VW part that is the same as my Porsche part number.Anyone know the VW part number. Will be easier to go to a VW parts dealer than Porsche.Probably cheaper also
10-05-2003, 05:57 PM
#5
Burning Brakes
Michael -
Most likely it's the failure of the pressure sensing switches on the master cylinder, change both and make sure your parts guy orders the correct one's, look @ yours.......there are two styles one has two contacts the other has three. A very easy DIY just make sure to position a rag to catch the seeping fluid and don't forget to correctly and fully bleed the brakes when your through
.
Good Luck
Most likely it's the failure of the pressure sensing switches on the master cylinder, change both and make sure your parts guy orders the correct one's, look @ yours.......there are two styles one has two contacts the other has three. A very easy DIY just make sure to position a rag to catch the seeping fluid and don't forget to correctly and fully bleed the brakes when your through
.Good Luck
10-06-2003, 10:51 AM
#7
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I just had this problem on my 83SC.... it was the two pressure switches on
the master cylinder.Easy swap out... no problems.Do a search on Pelicanparts for very good instructions on how to do this.
the master cylinder.Easy swap out... no problems.Do a search on Pelicanparts for very good instructions on how to do this.
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03-25-2023, 09:53 PM
#8
Interesting brake lamp issue - solved
I have a 1983sc and was told by my shop that the drivers side brake light was out. Since they wanted $58 to fix I decided to do it myself.
I found that both brake lights illuminated fine when the headlights were off, but the drivers side brake light stayed on when the headlights were illuminated. After trying several things including replacing the brake light bulb, I discovered a strange thing. Removing the bulb and turning it 180 degrees and then replacing it seemed to do the trick! Not sure if this is because the contacts are worn or if it is meant to work only in one orientation but thought I would share the discovery.
I found that both brake lights illuminated fine when the headlights were off, but the drivers side brake light stayed on when the headlights were illuminated. After trying several things including replacing the brake light bulb, I discovered a strange thing. Removing the bulb and turning it 180 degrees and then replacing it seemed to do the trick! Not sure if this is because the contacts are worn or if it is meant to work only in one orientation but thought I would share the discovery.
