Stew F Posted 8May, 2014 Report Share Posted 8May, 2014 I received a letter from the local constabulary today informing me that a member of the public reported that I have no brake lights on my 82 SC. I've read a lot of stuff on the web today about the switches being the potential culprit. Does anyone know of a source for an aftermarket one (2)? I haven't phoned my local Porsche Centre, but I suspect they will be a bit pricey. I saw some on Ebay but they are in the US of A. Their part number matches the genuine Porsche number, except for a H at the end instead of a G. $7.43 each + $13.85 for postage. Thanks. Link to comment Share on other sites More sharing options...
tazzieman Posted 8May, 2014 Report Share Posted 8May, 2014 Don't think new ones will necessarily work better. Go out at night at see how much foot pressure is required to activate the lights. Even if you have well-bled brakes , there is much more travel than a modern car. If you can't get any light there may be a problem. Otherwise a microswitch (~$) attached to the master cylinder will give you "modernised" sensitivity. Thread on pelican about this , I did it , not too hard. ...after wasting time and money replacing the pressure switches, which I suspect were fine in the first place, just an old design. Link to comment Share on other sites More sharing options...
Stew F Posted 8May, 2014 Author Report Share Posted 8May, 2014 We just went out and checked them. Definitely no lights - at all. I'm sure I saw them light up the other night when I was driving it though. Agree, it's an old system. Inherently problematic by design. Do you have the Pelican link? I'll check the fuse, but the tail lights work, and they're all off the same fuse according to the wiring diagram. I presume I can check the switches by depressing the pedal and reading the output with a multimeter or test light. Is there 1 switch for each side? Link to comment Share on other sites More sharing options...
tazzieman Posted 8May, 2014 Report Share Posted 8May, 2014 The link is in my previous post. Take the lenses off , check with the meter you're actually getting 12v or close to it when you press the pedal. Check fuses. Report back! Link to comment Share on other sites More sharing options...
Russ Posted 8May, 2014 Report Share Posted 8May, 2014 So nice of the member of the general public to tell the police and not you! How unaustralian of them Link to comment Share on other sites More sharing options...
tazzieman Posted 8May, 2014 Report Share Posted 8May, 2014 So nice of the member of the general public to tell the police and not you! How unaustralian of them Are you insinuating perpetraitor doesn't eat baby sheep on Australia Day? Link to comment Share on other sites More sharing options...
G5032 Posted 8May, 2014 Report Share Posted 8May, 2014 I have a spare pm me if ur interested in buying Link to comment Share on other sites More sharing options...
Stew F Posted 8May, 2014 Author Report Share Posted 8May, 2014 Tazzieman, I didn't see that. Didn't have my glasses on. I will try to have a look tomorrow. Stay tuned. Russ, I think, going by the date, time & location, it may have been a semi driver. When I took off from the lights I looked in my mirror and saw a guy walking back to his truck which was behind me. If it was him he made an effort, but wasn't quick enough, so I'll cut him some slack. Fortunately I didn't get an infringement notice or anything. Why are there 2 switches? Link to comment Share on other sites More sharing options...
tazzieman Posted 8May, 2014 Report Share Posted 8May, 2014 Why are there 2 switches? Porsche advanced safety feature of the day , 2 circuits so if one fails you can still pull up. Link to comment Share on other sites More sharing options...
Caledonian Posted 8May, 2014 Report Share Posted 8May, 2014 So nice of the member of the general public to tell the police and not you! How unaustralian of them Yeah! they must have been a foreigner..... Link to comment Share on other sites More sharing options...
Harvs11 Posted 8May, 2014 Report Share Posted 8May, 2014 So nice of the member of the general public to tell the police and not you! How unaustralian of them Would they have bothered if it was a Camry? Link to comment Share on other sites More sharing options...
webrest Posted 8May, 2014 Report Share Posted 8May, 2014 Very nice of that person to ring the police and offer up that info on your car. What a jerk. Link to comment Share on other sites More sharing options...
webrest Posted 8May, 2014 Report Share Posted 8May, 2014 Porsche advanced safety feature of the day , 2 circuits so if one fails you can still pull up. Interesting. There are two switches one for the front and one for the rear and I can see one switch failing or one hydraulic circuit but I can't reason why there would be no stop lights. At least one of the switches should be operational and that would send the signal to the stop lights surely. The fault must be somewhere else in the system.by my reckoning. Keep looking. It's nothing stupid like the wires have fallen off the stop light terminals. Can only assume you have pulled out the cover board in the boot and had a physical look Link to comment Share on other sites More sharing options...
tazzieman Posted 8May, 2014 Report Share Posted 8May, 2014 I'm not sure who invented/sold the first car with the dual hydraulic system (which was mandated by US legislation). But an early Porsche from 1898 did sport a dual system of sorts! Consider its advanced dual-circuit brake system. In addition to mechanical brakes acting on the rear wheel, the car also had electric brakes that could stop the car using the motor. Link to comment Share on other sites More sharing options...
Stew F Posted 9May, 2014 Author Report Share Posted 9May, 2014 Interesting. There are two switches one for the front and one for the rear and I can see one switch failing or one hydraulic circuit but I can't reason why there would be no stop lights. At least one of the switches should be operational and that would send the signal to the stop lights surely. The fault must be somewhere else in the system.by my reckoning. Keep looking. It's nothing stupid like the wires have fallen off the stop light terminals. Can only assume you have pulled out the cover board in the boot and had a physical look I haven't had a chance to check anything yet. Plus the weather's a bit crappy for being outside. So I decided to stay inand get some money making work done. I agree. Unlikely that both switches should fail together, unless one was already crook. I said in my first post that I thought the tail lights and brake lights were off the same fuse, but after a closer look (with my glasses on) it's only the brakes on fuse #5. Shall start there. Link to comment Share on other sites More sharing options...
Stew F Posted 11May, 2014 Author Report Share Posted 11May, 2014 Finally had a chance to check z lights. Fuse OK. So if I jump the terminals on one of the switches and press the brake pedal I should have lights, yes? Link to comment Share on other sites More sharing options...
Simonk Posted 11May, 2014 Report Share Posted 11May, 2014 One of the switches probably clagged out a while ago. Speak to James at Autohaus Hamiltons. I got two delivered to Melbourne cheaper than Pelican. Make sure you order the correct ones. Some were two prong, some were three prong. Link to comment Share on other sites More sharing options...
webrest Posted 11May, 2014 Report Share Posted 11May, 2014 Finally had a chance to check z lights. Fuse OK. So if I jump the terminals on one of the switches and press the brake pedal I should have lights, yes? Link to comment Share on other sites More sharing options...
webrest Posted 11May, 2014 Report Share Posted 11May, 2014 If you jump the terminals you should have brake lights without using the brake itself. What you need to do is hook a multimeter set to ohms or audible and see or hear if the circuit closes when the pedal is depressed Link to comment Share on other sites More sharing options...
Stew F Posted 13May, 2014 Author Report Share Posted 13May, 2014 After a bit of testing, followed by a few beers and a nice mother's day lunch, it turns out it was those switches. As someone said, one probably packed up long ago. So I phoned Porsche Centre Adelaide. $71 each. Same part off the web from a VW place (same part number as genuine part) $8 plus postage. Just got to order them now. Thanks all for your help. Link to comment Share on other sites More sharing options...
webrest Posted 13May, 2014 Report Share Posted 13May, 2014 So I phoned Porsche Centre Adelaide. $71 each. Same part off the web from a VW place (same part number as genuine part) $8 plus postage. Just got to order them now. Thanks all for your help. And they wonder why think we are being gouged. Link to comment Share on other sites More sharing options...
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