Where is the brake light switch on the brake pedal

[liifesfun]

Hi all

My cruise cuts out intermittently and it (the fault) appears to be linked to the brake switch, as it works again if I hit the brake pedal and then pull back on the pedal with my toe hooked behind it, suggesting the contact in the brake switch is faulty.

I stuck my head in and expected to easily see the switch but it wasnt apparent, I did a search on this site and couldnt find anything.

Out of curiosity does anyone know if the switch has a single or dual contact and if it is make or break (sorry thats techo speak), logic would say its a break contact as a fault condition is likely to be open circuit and for safety it is best that the cruise is off rather than the it failing to switch off when you hit the brake pedal.

I was expecting this as 5 minute job and hope it is, if I have missed something obvious, I will graciously accept referrals to a good optometrist.

Bruce

[RFM]

The brake light switch is equipped with a triple contact, if the brake pedal is pressed the contacts are closed. The body color of the switch is brown for European cars en located up and on the front of the brake pedal. Remove the heater duct for more room, turn the switch to the right approx. 90 degrees and pull out. To install lubricate the locking area with a small amount of grease, push and turn the switch 90 degrees to the left. It's sounds controversy to turn right to unlock and vise verso, but it is more easier.

[liifesfun]

Dont you love this site, 24 minutes for a response, I reckon you could get an answer and do the repair quicker than an "auto club" could get out and jump start a flat battery!

[liifesfun]

UPDATE - $0 fix

Porsche centre (OPC) supplied part number 99661311302, they have indictaed that this is the updated/ sueprceded part. It is physically a little different, the new one it has 4 terminals as opposed to 3 but fits the connector OK (this probably doesnt matter electrically, I couldnt test at the time) BUT its about 5-10 mm longer, I couldnt get it to lock in and wonder if this is why, any one experience this? 97/98 2.5l tip.

Good news - I pulled apart the old switch and can answer my question previously. For those techos - The switch is electrically a changeover switch with 3 contacts (as opposed to terminals) in the normal position (meaning without the brake pedal pressed) the switch is closed for the cruise control circuit, which validates my previuos logic that for safety if the switch or circuit fails is most likely to go open circuit thus swiching of the cruise control. When the pedal is depressed the switch changes over and operates the brake lights. For reference, the switch is mounted in front not behind the brake pedal, so the switch releases when you press the pedal, the significance is if you test the switch whilst not mounted but plugged into the quick connect socket, the brake lights will come on when the switch is released (normal mode) and go off when you push the plunger.

As I had the switch apart I took a metal finger nail file and gently filed the contacts as they were pitted and sprayed with contact cleaner plus the connector, went back together perfectly.

Drove the car $100km today the cruise works without fault!

I'll post a photo sometime

Bruce

The brake light switch is equipped with a triple contact, if the brake pedal is pressed the contacts are closed. The body color of the switch is brown for European cars en located up and on the front of the brake pedal. Remove the heater duct for more room, turn the switch to the right approx. 90 degrees and pull out. To install lubricate the locking area with a small amount of grease, push and turn the switch 90 degrees to the left. It's sounds controversy to turn right to unlock and vise verso, but it is more easier.

[liifesfun]

Dear friends,

I just noticed that its nearly 2 years since the brake switch / cruise control cut out problem.

UPDATE - its still all OK, the $0 fix is still working.

Without trawling back through the threads, my cruise control kept dropping out and I finally worked out it was the brake switch causing the problem. I pulled out the switch, dismantled it ( yes you can pull them apart) and the contacts were burnt, so I filed them with a nail file. I commented on this forum that if I got 12 months service I'd be thrilled, well its now 2 years.

Bruce

UPDATE - $0 fix

Porsche centre (OPC) supplied part number 99661311302, they have indictaed that this is the updated/ sueprceded part. It is physically a little different, the new one it has 4 terminals as opposed to 3 but fits the connector OK (this probably doesnt matter electrically, I couldnt test at the time) BUT its about 5-10 mm longer, I couldnt get it to lock in and wonder if this is why, any one experience this? 97/98 2.5l tip.

Good news - I pulled apart the old switch and can answer my question previously. For those techos - The switch is electrically a changeover switch with 3 contacts (as opposed to terminals) in the normal position (meaning without the brake pedal pressed) the switch is closed for the cruise control circuit, which validates my previuos logic that for safety if the switch or circuit fails is most likely to go open circuit thus swiching of the cruise control. When the pedal is depressed the switch changes over and operates the brake lights. For reference, the switch is mounted in front not behind the brake pedal, so the switch releases when you press the pedal, the significance is if you test the switch whilst not mounted but plugged into the quick connect socket, the brake lights will come on when the switch is released (normal mode) and go off when you push the plunger.

As I had the switch apart I took a metal finger nail file and gently filed the contacts as they were pitted and sprayed with contact cleaner plus the connector, went back together perfectly.

Drove the car $100km today the cruise works without fault!

I'll post a photo sometime

Bruce

The brake light switch is equipped with a triple contact, if the brake pedal is pressed the contacts are closed. The body color of the switch is brown for European cars en located up and on the front of the brake pedal. Remove the heater duct for more room, turn the switch to the right approx. 90 degrees and pull out. To install lubricate the locking area with a small amount of grease, push and turn the switch 90 degrees to the left. It's sounds controversy to turn right to unlock and vise verso, but it is more easier.