Volkswagen Brake Light Switch

Posted by Redhexagon On 2023/1/15 17:14:16

My brake light switch only turned the brake lights on if I stood hard on the pedal. Like...put yourself through the windshield level of hard braking. That's not good.

I'm a career auto parts man, and I searched through every catalog I have going back to the 1970's, and none had the 3-pin brake light switch for Torsion-Level cars, It appears this switch was made by Casco for Packard for only two years, and was never produced or sold aftermarket.

I bought a NOS switch from a Packard part supplier for $130. It didn't turn the brake lights on at all, and began leaking fluid from the crimp on the switch body after about the second pedal press.

A second $130 NOS switch did exactly the same thing. Both switches were leaking black goop out the threaded end after I removed them. My guess is there is a rubber diaphragm inside that is rotten after 68 years of sitting on the shelf and that black goop is the rubber disintegrating.

Many of you have heard of the 1970's Volkswagen switch (NAPA # SL159) that uses slide terminals instead of pin terminals. I bought one and it threads into the T-fitting on the frame rail perfectly. I created an adapter harness that plugs into the original Packard connector with individual pins, and to the Volkswagen switch using a Napa # EC428 connector.

The original Packard harness has three wires:

Pink: Power feed from the fuse panel. Hot at all times.

Light Green: to Torsion Level.

Dark Green: to brake lights.

If you are looking at the top of the Volkswagen switch, rotate the switch until the terminals are at the 3:00, 6:00, and 9:00 positions. Connect the pink wire to the 9:00 terminal, the light green wire to the 6:00 terminal, and the dark green wire to the 3:00 terminal.

The Volkswagen switch is very sensitive. It turns on at about 100 PSI. I did some testing on the vehicle and found that the brake lights come on just before the brakes begin to engage. However, I have had zero problems with the switch staying on after the pedal is released.