Brake lights stuck on, changed the switch, no dice..

[BTERRY1]

As the title states my brake lights are always on.  Ordered a new brake light switch and swapped it out no dice.  Lights still stuck on.  Pulled fuse 7 row B and lights off.  Took both switches old and new apart and cleaned, reassembled and still no luck.   Can I jump the black and yellow wire in the female end of the connection to isolate it a bad new switch.  What should I do next?

[Loren]

Are you sure you changed the right switch?

If you have cruise control (most US cars do) then you might have changed the cruise control switch instead of the brake light switch.

[BTERRY1]

thanks Lauren i will take another look again when i get home.  do they look basically identical?  i was up side down and backwards to get in the spot and thought for sure i was in the right place, but you never know....

 

know that i think about it i am pretty sure cause i was able to start the car with the switch out when testing between the old and new.

[Ahsai]

The brake switch that sends power to the brake lights should have a black wire and a black/orange wire going into the switch. There is a black/red wire going into the switch too if you have cruise control. Also, once the switch is removed, there should be no power to the brake lights. Normally the switch is OPEN between the black and black/orange wires.

[BTERRY1]

thanks Ahsai - the switch I was fiddling with this morning had 2 wires coming out the back of it.  I thought one was black and one was yellow.  When the car was running and I removed the switch the brake lights stayed on.  Is this further evidence I was having a senior moment and working on the clutch switch instead?

[DBJoe996]

There are two switches on the brake pedal.  One is for the brake lights, the other for the cruise control.  Make sure you are working/replacing the right one.  See here http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=702-00

[Ahsai]

12 hours ago, DBJoe996 said:

There are two switches on the brake pedal.  One is for the brake lights, the other for the cruise control.  Make sure you are working/replacing the right one.  See here http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=702-00

Hi Joe, are you sure? Mine (MkII) has a single switch on the brake pedal and two switches on the clutch pedal - one for cruise control and one for starter interlock.

[Loren]

Two switches on the brake pedal - one for brake lights and one for cruise control (if you have that option).

 

Two switches on the clutch pedal - one for clutch disengage and one for cruise control  (if you have that option).

 

[Ahsai]

That's interesting, Loren. I have cruise control but has a single switch on the brake pedal with 4 wires going in. The wiring diagram indicates that single switch feeds both the brake light and the DME/cruise control module (SPDT contacts inside the switch for the two circuits).

[Ahsai]

Good info here for the OP

 

http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement.htm

 

 

[BTERRY1]

morning update.  I confess, i am an idiot.  was working on the clutch as Lauren suspected.  all is well.  face palm........

[DBJoe996]

Hey Ahsai!  So I was going by the parts listing...but...you got me to thinking so I crawled under the dash and looked.  I have cruise control and I can see only one switch on the brake pedal.  Go figure.  99 C2  So I think in our cars the cruise control detects the  brake application from the single brake lamp switch, which also explains why when the bulbs are burned out the cruise control doesn't work..

 

Edited May 5, 2017 by DBJoe996

[Ahsai]

6 minutes ago, DBJoe996 said:

Hey Ahsai!  So I was going by the parts listing...but...you got me to thinking so I crawled under the dash and looked.  I have cruise control and I can see only one switch on the brake pedal.  Go figure.  99 C2

 

I also crawled under the dash last night just to make sure I'm not crazy :) I also have one brake switch. It makes sense because from the wiring diagram, it's clear that the single switch controls both the brake light and the cruise control.

[Loren]

Looks like you are both right. I looked at all the wiring diagrams.

MY1999 through MY2001 has two brake light switches.

MY2002 - MY2005 has one brake light switch.

[Ahsai]

Um, Joe's '99 has only one switch and I was only able to find one brake switch in all the wiring diagrams, regardless of MY.

Not that it matters to the OP now anyway.

 

 

Edited May 5, 2017 by Ahsai