Once you mount the aftermarket switch at the pedal,
you snake the wire and feed it into the original switch connector at the M/C ?
So, you'd also need additional spade adapters and longer wires.

Interesting alternative, but I am not a fan of aftermarket wires running throughout the car.
Makes things confusing for the next owner.

Forget the pedal, easiest way is to mount the mechanical switch on the master cylinder. Tons of information here on various mounting methods.

It fits and I filed the rest.
Nope...

swapping out the brake light switches is a job that I still have nightmares about, almost 4 years later. the original switches made it almost 25 years, hopefully the replacements make it that long.

The factory put in two switches for redundancy. The fact that the both get old at the same rate just means you need to likely replace them every 25 to 30 years as maintenance. It is not that hard to do, and sure beats some home made bodge. The factory moved away from the pedal mounted switch for a reason. On my 914 I had to replace that switch twice because of getting in the car with wet feet and the pedal area is a dirty area.

If an old fat man like me can replace them fairly easily, anyone can. It is your car, do to it what you want, but check your brake light function regularly regardless what system you go with.

Hard to disagree with? ;)

Ordered a cheap switch for $8.
It matched the part better than the ATE brand
Correctly sized 22mm, so I got it installed easily.
Verified the brake lights now work again with a light touch.
I now have one brake light switch, and the car is back on the road.

Touchdown!

Air bubbles stayed away?

A little bit of fluid dropped out onto the catch rag.
Brakes light up with barely any pressure.
Brakes work fine, but I'll flush the fluid in the Spring.

That's good, mine drained out, I lost half a 'tank.'

I went through this (twice!) with my '84. The second time, I took apart the switches and found the contacts quite damaged due to arcing. When I put the second set of switches on, I added a relay to protect them. There are several threads on the problem here, if you're interested.

There are 2 switches to carry the amperage of the brake lights from what i understand. The switches are rated at 6amps? I think that one switch will fail sooner than 30 years.

How did you take apart the switch? I'd like to take apart my old one.

I used a Dremel around the outer edge of the case to free up the switch guts.

It's a pretty common problem as the cars age

https://forums.pelicanparts.com/porsche-911-technical-forum/422337-anyone-hear-about-solution-failed-brake-light-switches.html#post4087694

Subscribed.
 

Following along as this is next on my "to-do" list. I am in the process of trying to make the Cruise Control unit in my 1982 911sc function.

Just noticed that my brake lights do not light up anymore.
I need to revisit. Last time in 2021, I only replaced one switch.
Could it have failed already? I barely ever drive the 911 the last few years.
Could the switch be stuck? Can I remove and jam a pick in there?
Could there be an air bubble at the switch?

Which fuse is for brake light? I should check that also

Diagram for 86 Coupe shows this is fuse number 4 (8A) on fuse box I. Should be a green/blue wire.

No, it is fuse #7
https://imgur.com/a/p0rGOjM

My fuse is intact.
I will order a new switch

113945515h

Don't despair.

Working on your car is still part of the hobby, Sugar.

I enjoy every minute of it, contortions and straining included trying to squeeze into small spaces while trying to thread a needle thru a hole.

What's up ?

Post a pic of your predicament.

Yes, fuse 7 is absolute position. But this same fuse is labelled number 4 on fuse box I on factory diagram. That's why I mentioned fuse box I.

The complete fuse row is divided in 3 parts on the factory diagram. One that starts from windshield and bears no fuse box number on factory diagram, next one is fuse box I and has 10 fuses labelled 1 through 10 (amongst which number 4 is the fuse you are looking for), and the last one is fuse box II and has 8 fuses labelled 1 through 8.

Does the brake light switch removal potentially introduce an air bubble bleeding scenario?
What if the switch is fine, but there is an air pocket in the switch?
Is this possible under this design?

I switched out the 2 year old switch for a Beck/Arnley 201-1087 Stop Light Switch.
The brake light is now working. Was not air bubble or bleed issue.
So, the cheapo switches fail fast.
Can't remove front switch since its blocked by brake line.

What a nightmare of a simple repair.
Remove carpet, remove shield,
detach cross brace (annoying bolt access at bottom)
detach 2 hoses, detach electrical plug,

22mm switch is so blocked by stuff.
1/4 turn at a time.
Back on fire

Getting air hose re-attached was also a hassle b/c it's not clear if the underside is seated.
Electrical plug also gets in the way.
I also started to attach the cross brace to the wrong screw hole (for back shield)

I was glad to find this thread when I recently found out my brake lights only come on when I nearly depress the pedal to the ground. Meaning under light braking I have no brake lights.

I didn't cheap out since brakes are essential and ordered two ATE switches. My old and new 3 prong switches are all 24mm BTW. My car is a 1977 911S and reading this thread I had feared it was going to be horrendous. But honestly I was done in 20 minutes. Not much to get out of the way and using a straight and a box wrench I replaced one at a time. The switch near the booster dripped a bit but the one furthest from me did not. Anyway I made sure it was a quick out with the old and in with the new.

Once I was done I checked out the result and I was gutted to see the new switches made no difference! Mind you I checked with the engine off so no boosted brakes so to speak. How can this be? What is causing my brake lights to only come one that late in the pedal travel.

How do I fix this? Is my master cilinder failing and not building enough pressure? Can or should I install the early switch at the pedal since my pedal box has provision for this and jumper the wiring?

I may be jumping to conclusions but could it be that my master cylinder is failing and not building enough pressure for the switches to activate until I depress the pedal fully to the floor?