brake light switch

[tenaciousdave]

At the moment none of my brake lights are working, they were all flickering on and off for a short while yesterday when the pedal was depressed but now they are completly gone. I changed a fuse just to make sure it wasn't that but I'm pretty sure its the brake light switch.


I have a '02 3.2 tiptronic S and want to double check if its this switch ASAP in case I cannot put the car into gear soon to take it for repairs. (normally the break pedal needs to be depressed before you and push down the button and put it into park, reverse etc..)

Would anyone have a few tips at the best way to get to this switch or has anyone come across a guide online on how to do it?

cheers
David

[Gary in BR]

Last week I had my second one go out on me in 160k miles.
My dealership could not get one for a week.
I thought back and remembered that I heard you can clean the switch.
Knowing that, I climbed under the dash and removed the switch, took it apart. and cleaned it. Now the lights work like they switch was new.

The brake switch in my 99 5 speed is located under the dash at the end of the brake pedal it is a plunger switch. Turn the switch 90 degrees, you will feel it release, pull it toward the drivers seat, at this point you can unhook the plug. Now the switch is in your hands.

Pop it apart with a thin screwdriver you will see some metal contacts, I just cleaned them with the screwdriver and put everything back together.

Its pretty easy.

I am sure someone has a better description and maybe pictures.

Good luck.

[tenaciousdave]

thanks for that gary, I'll give it a go when I get home. Hopefully it will work

[Lil bastard]

The Stop Light Switch for the Tiptronic is PN# 996.613.110.01.

It's located in a bayonet mount in the Pedal Block - disconnect the electrical connector and turn the switch body 90°.

A common problem is that if the switch is 'overpressed' the switch travel or pedal travel up to the switching point is lost.

This results in the brake lights being always on or flickering when travelling over bumps.

In vehicles with cruise control, the cruise control can be accidentally deactivated from vibrations.

From the Factory Repair Manual:

The switches must be readjusted after any work in which the brake pedal is moved out of its "normal" position (for example, work on the pedals or on the brake unit).

Checking stop light switch adjustment:

The pedal must be felt to travel approx. 5 to 10 mm before the brake light lights up. At the same time, check (make sure) that the brake light lights up before the pedal meets perceptible resistance or before brake pressure builds up.

Adjusting switch in the event of insufficient pedal travel:

There are two possible ways of adjusting the switch if the pedal travel to the operating point is too small.

1: Press brake pedal and pull out plunger of the switch.
Release pedal. Check adjustment.

2: Release switch by turning it 90°, and pull it out of its installation opening.
Pull switch plunger out of the switch as far as it will go.
Reinstall switch.

When fitting the switch for the first time, it is important to press vertically against the bearing surface. It will otherwise not be possible to lock the switch (90° turn), even using a lot of force.

Note:

The switch might not fit in its seat without play after it has been installed and removed several times.

As soon as the switch perceptibly "wobbles" in its receiver, it must be replaced by a new switch.

Adjusting the switch if the pedal travel is too large:

Press the pedal; press the plunger into the switch by one notch (audible click). This decreases the pedal travel to the operating point by approx. 3 ... 4 mm. Then recheck the adjustment.

[Wret]

I had the same problem a couple months ago. I ordered the switch from Pelican but in the mean time I took out the switch, cleaned it and reinstalled it. Worked for about a day. I took the switch out agaian and bent the contacts so they would make better contact. This worked and I still haven't put in the new switch.

[tenaciousdave]

yeah I need to get a new switch i think. I wasn't able to take it out fully. A bit too concerned about how I should take it apart as it gives a lot of resistance. dont want to pull the wires too hard and do more damage. If I twist it a bit it seems to work for a few hours but have a service boooked in for monday anyway so will get them to replace it.

thanks for all the help though

[socratic]

I did mine last year and remember swearing at how much force I needed to exert to take it out and especially putting it in. So don't despair, it it literally is a few minutes and not necessarily worth taking it in to do, especially if you have to pay them.

I see that Lil Bastard posted a hint:
----------
When fitting the switch for the first time, it is important to press vertically against the bearing surface. It will otherwise not be possible to lock the switch (90° turn), even using a lot of force.
----------

I can't remember if this would have helped or not.

It also seems to be a poorly designed and/or a cheap little product too, not giving me great confidence that it won't wear out again in a few years.

[gregdacat]

I am changing my brake light switch. The old one popped right out. I connected the new one to the wiring connector and have now spent the last 2 hours trying seat the switch back in the mount. I have tried every possible angle and amount pressure but I cannot get it to turn the 90 degrees to lock it into the mount. HELP!

[tommy986]

if i recall correctly, it only will turn one way. so you turn it the same way to seat it as you did to removed it. The other thing i noticed is that the plastic tabs on the replacement switch seem ever so slightly longer than the originals. I used a finger nail file to remove a VERY slight amount of plastic.

Tommy

[gregdacat]

Thank you Major Tom you are a life saver. I could not find a finger nail file, but I had some sand paper with boulder-sized grit. I gave each side of the switch a quick swipe and that bad boy went right on just like the old one came off. I have working brake lights once again! I wish I had done that 2 hours ago.

[igk]

so glad i found this thread.
my psm and abs lights came on yesterday and i noticed that the brake lights weren't working last night. called my local porsche dealership and the parts department is closed today for inventory. ended up stumbling on this thread.
turns out that my switch just needed a good cleaning. took out the switch, opened it up, cleaned out all the metal contacts with isopropyl alcohol. put everything back together and the problem appears to be cleared up. it's daytime now, and i'm by myself, so i can't actually see the brake lights, but the dash indicators have disappeared. hopefully that's all it needed.

[igk]

i just opened mine up and cleaned the metal contacts. seems to have done the trick.

[Breadman]

Hi i have no brake lights on my 99 boxster took out relay switch(which was completely loose not turned in) cleaned it up and reinstalled. still no lights. just got car last week so do not know if brake lights ever worked. any help?

[Meir]

disconnect the wires from the switch.
use another wire (or a paper clip) to make a loop between the two wires.
turn the ignition on and go check if the brake lights works.
if it dose, get a new switch.
if it doesn't, then you will have to troubleshoot the rest of the system (fuse,bulbs,wires...)

[tommy986]

This is a 4 wire switch.
2 wires are for controlling the cruise control, the switch completes this circuit when the pedal is NOT depressed.

2 wires are for brake lights. The switch should complete that circuit when the pedal is depressed.

You could check the switch with an ohm meter for continuity on each of the circuits.

[Breadman]

Thanks guys i have ordered a new switch. hopefully that will do it. anyone done an ignition switch? mine occasionally will not turn over but all lights etc are on. what do i need for a tune up besides plugs wires filters etc? just bought car last week. got a good deal and know i had to do some stuff

[Gforrest2]

Okay, so my brake lights quit working today. Fuse, looks good, managed to get the plunger switch out (what a PITA and I have small hands). Put the ohm meter on it and it seems to work, i.e., continuity with the plunger out no continuity with the plungr in. Now what???? I do hear a clicking sound when I press the brake pedal fully. Is there another switch somewhere? Wow, this is frustrating. And yes, I checked the bulbs just in case all three went out at the same time. Guess it's time to pull the wiring diagram out. Is there a way to jump the connector where the plunger switch goes to see if the lights will come on ?

[particlewave]

Take it apart and clean it anyway. Re-spring the contacts a little, too. May as well since you have it out and I wouldn't go by the ohm meter alone.

[Gforrest2]

I'm having one of those days. Last thing I checked were the bulbs. It would be just like me to go through all this and then find out the bulbs were bad.

Well, call me an idiot, but I didn't realize you have to have the ignition on for the brake lights to work. Doesn't work that way in my other 4 vehicles. Oh well, live and learn. Brake lights work fine. Glad I didn't take it in. So far it just cost me an hour of wasted time and some skinned up knuckles.

[particlewave]

Ha! We all have those days.