After yet another failure of my Brake Light switches... I thought I'd share my experience.

In the past I have purchased "aftermarket" 3-prong switches from various suppliers, over the many years of ownership of my 84 Westy.  It seems that about every 3 or 4 years, both switches fail and need changing.

I flush the fluid annually, and I actually replaced the Master Cly 4 years ago, along with the brake-light switches.  Well, the switches failed again, so this time I went with P/N: 340038A ATE, and purchased with a "lifetime" warranty at https://www.fcpeuro.com/products/porsche-brake-light-switch-ate-113945515g#fitment

Bingo, brake-lights work again!

A tip on replacing, use a 24mm deep well socket on the rear switch, with an extension, and you don't have to remove the dash support bracket.  Also, be sure to keep the cap on the brake fluid reservoir, and put plenty of paper towels under the switch.  Do a quick swap, and you are done.  The entire job should take less than 30 minutes.

Hope this helps!

Jack R.
84 Westy Wolfie