Brake Light Switch Demons

rzeller · Post by **rzeller** » Wed Apr 05, 2006 11:56 pm

I swear that my buggy likes the garage more than the road. Since Jun '05 I have had three brake light switches fail (the latest one today). I replaced the first one in Jun '05, the second one in Oct '05 (588 miles since the first one), and the third one in Mar '06 (402 miles since the second one). The last one (#3) just failed today (237 miles on it). I have the standard VW master cylinder and brake switch set up. I know these things are known to fail, but this seems a little excessive. Not to mention I'm getting less miles out of each new one. Thinking that I might have an electrical issue instead of a mechanical one, I checked the voltage across the leads and it read 12V. That seems right, doesn't it? Additionally, each time they fail I make sure the circuit is good by shorting the leads together to see if the lights activate. They do. If it's not electrical, what can be causing the mechanical failure? I was under the impression that the switch is activated by brake fluid pressure. True? Any ideas? The weather is just too nice not to be driving my buggy. I won't drive it knowing that the brake lights don't work. Hell, people around here run into the back of perfectly good cars/trucks every day. I don't want to increase my odds. Thanks for the help. Bud

newmanx59 · Post by **newmanx59** » Thu Apr 06, 2006 12:08 am

Bud, What are you using for taillights? Is it possible there are too many amps being drawn thru the switch?

rzeller · Post by **rzeller** » Thu Apr 06, 2006 12:21 am

Jerry, I'm using beetle tail lights. I haven't checked the bulbs though. Bud

newmanx59 · Post by **newmanx59** » Thu Apr 06, 2006 12:42 am

Stock VW taillights shouldn't cause a problem. If you are into experimenting you might want to run the brakelights thru a relay to see how long the switch lasts. You might also want to try using an old style Ford brake light switch, in place of the VW switch.

rzeller · Post by **rzeller** » Thu Apr 06, 2006 1:11 am

Jerry, I'd like to say I'm playing dumb, but.... when you say old style Ford switch what do I ask for at a parts store? Does the Ford switch screw into the master cylinder just like the VW? Thanks, Bud

Olli · Post by **Olli** » Thu Apr 06, 2006 1:45 pm

Jerry, Could you please elaborate on the Ford switch? Thanks. Olli

gregr · Post by **gregr** » Thu Apr 06, 2006 1:46 pm

Here's the mechanical brake switch I put in.... brake switch

fubar · Post by **fubar** » Thu Apr 06, 2006 6:05 pm

Maybe try a different parts house???????They should last a long time. Some places like Napa sell some genuine garbage that is not as good as a wrecking yard part. Look for that German label.

domorr · Post by **domorr** » Thu Apr 06, 2006 6:19 pm

I would try bleeding your brake system. There might be some air trapped in there not letting the switch do it's job.

rzeller · Post by **rzeller** » Thu Apr 06, 2006 7:04 pm

Guys, Thanks for the suggestions (I'd like to learn more about the Ford switch). I talked to my mechanic about it this morning and he tells me that he is not surprised. He said the switches he is getting from his supplier are crap. Since I have a two wire switch on my buggy, I am going to try a three wire one (one more attempt on using the stock switch) to see if it works any better. If that fails I may resort to the idea that Greg had with the little floor switch. By the way Greg, I replaced the first switch for the same reason you did. The switch wasn't activating unless the wheels were locked up. Since that drew a lot of attention at red lights, I decided I needed a change. Thanks, Bud

fubar · Post by **fubar** » Thu Apr 06, 2006 10:46 pm

The stock VW worked well for a lot of years. Reproduction parts that some places sell are just low quality. The fluid pressure at the switch should not be an issue. I don't see how a 3 wire would work better???? Try a wrecking yard Bosch or spend the extra $2 at the dealer?????????????

Tom-Kathleen · Post by **Tom-Kathleen** » Thu Apr 06, 2006 11:06 pm

We have used switches purchased from the VW dealer, and they don't last long. I am interested in the Ford switch also. I cross drill rotors for a company in Vernon (ECI) who sells brake kits for street rods and muscle cars, and he recommended the Ford switch to me a while back. I will be there tomorrow, so I will see if I can get a P/N. Tom

newmanx59 · Post by **newmanx59** » Fri Apr 07, 2006 12:08 am

I worked in an auto parts store around 1975 so I would say the switch would fit an early 70's Ford product. It will screw into the master cylinder like the VW switch and it has 2 mushroom style connectors on it. Checkout this link...there are a bunch of them.

http://cgi.ebay.com/ebaymotors/Desoto-F ... otohosting Now that you know what they fit you can order them at the local parts store for a lot less cash.