Edward

A moment of venting: my goodness, on the 993 the brake light switch has never failed. But on my 1982SC ...argh!!

OK, I hate these dang pressure switches ...why do they have such an abysmally short life, or am I just having crud luck with switches?
So the bottom line: has anyone made a bolt-in kit to bypass these stupid pressure switches with a simple switch that is actuated by the pedal lever (like every freakin car I've owned for decades!!!!) . Sorry, I just had to let that one out. But yes, please give me some good news, someone!

Edward

Cloggie

Its easy to fit a relay and the problem goes away permanently....I have gone through several sets of switches in my time, has a colleague slice one apart and from what we can tell a little crap/fluid gets into the contacts and then the switch is Fubar.

Here is a circuit that works fine....just use a standard 30a Bosch or Hella relay...

Bill Verburg

I switched to a mechanical version decades ago

Cloggie

Yes, if you use the earlier Porsche mechanical switch its as reliable as an anvil....or did you use an aftermarket switch?

I could not find one I liked, hence the relay....and it too has been bulletproof....

Edward

Thanks for that gents. But Bill, sir, don't tease like that! What is the mechanical switch that works with these G-cars ...I'd love to put the bucks into getting this fixed forever instead of anther pair of switches and contorting myself into the trunk! I trust this is fabbed solution replete with bracket, switch, etc? Thanks!!!

Edward

Bill Verburg

the switch is from a '72/73 911
switch 911.613.411.00
bolt AM 4x10 900.146.011.02
washer A 4 , 3 900.114.014.01

Edward

Ahh, so not an aftermarket drop-in kit, then. Great specifics with p/ns ...thanks sir!!
Now pardon me for asking the obvious, but where (in the pedal cluster, I presume) does the switch go when I get it? Do I fab my own bracket? Any link, or even pics to send me in the right direction?

Edward

Bill Verburg

Here's mine, the bracket was already there, don't know about on newer cars

Cloggie

I know for sure my '89 G50 does not have it, else I probably would have used it rather than the electrical circuit I posted.

I think though on cars with power brakes, like the OP's '82, I also do not think that bracket was there as the master cylinder is moved and that washer that actuates it is right on the M/C input shaft...so I don't think it will work as simply with the power brake system.

I can't remember the details when I switched my '75 911S to Turbo power brakes I know that pedal cluster did not have the switch mounting tab and I was stuck with the electrical/hydraulic switchs which I rapidly became unhappy with.

So, let's hear how this turns out!

Bill Verburg

You might also look into the 964/993 versions

r911

get a PET and see if the p/n changes; diagram may show something too

Edward

All good info! I will have to first check my pedal cluster ...an 82SC and see what I find. Big thanks, guys, esp for the pics !

Edward

Bill Verburg

My car is a '76 , no power brake booster

My guess is that the "77 up cars w/ boosted brakes won't have the earlier bracket, but it never hurts to look

Any switch will do, the brake light just need an on/off signal

pressure loss warning function is another issue entirely

Cloggie

Yes, and there were two types of brake pressure differential warning, one was as per the schematic I posted which effectively uses the 3 wire switch and a fancy crossover wiring system to actuate a light when one switch closes under pressure and the other remains open. The other style (I think post-87) uses two wire switches and a little circuit boardthat runs the warning light cluster to the right of the steering wheel - also lights up for park brake, pad wear.