Beetle Cabriolet roof F171 switch work around.

I think many of us are familiar with the F171 switch problem on the roof of Cabriolet beetles, and the VCDS video is a fabulous resource.

For background the F171 is clipped on to the hydraulic ram on the RH side of car, and it is actually 2 x micro switches on one assembly one switch sends a roof open signal, the other (the rearmost) is responsible for sending the roof closed signal, this one seizes, and constantly transmits a roof closed signal.

This results in the F171 switch sending both open and closed signals at the same time, and the roof just stops dead!

Recently I was working on this, and decided rather than fit a new switch (1Y0 959 985A £42) which is known to cause the problem, and will undoubtedly do so again in the future I utilised the existing one and installed a push button latching switch into the wire carrying the (permanent) roof closed signal.

So now, when the roof is half way open, simply press the button, this stops the "roof closed" signal from the F171 dead in it's tracks. Then, when closing the roof and it's half way closed, hit the button again which re-instates the "roof closed signal."

I know it's a workaround, but to my mind it's easier to throw a switch and definitely remove the roof closed signal than jiggle the rear of the roof up and down in the hope that it trips the micro switch.

It works for me, and I dare say it could possible be done with a changeover relay being operated by the "roof open" part of the F171 switch, thus removing the influence of the stuck "roof closed" part of the switch.

The wire carrying the closed signal is the one with the darker green trace.

As I said I know it's a workaround, and some may groan at it, but it works!

I don't think there is anything wrong with doing this as it acts as an emergency override that you can use in the event where the roof just stops in a partially open/closed state and would normally just leave you in a situation where you might end up having to call out the breakdown services.

Reminds me a little bit of some people back in the day who fitted a cooling fan switch to allow them to override the fan and switch it on manually in the event that the temp sensor failed

GaryM said:

Reminds me a little bit of some people back in the day who fitted a cooling fan switch to allow them to override the fan and switch it on manually in the event that the temp sensor failed

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I did that 'cause there was no radiator fan temp switch that came on at a good temperature. The stock one was too high (wouldn't turn the fans on until the temp gauge close to redline) and the only other one I could get my hands on was too low (it would run the fan at times whilst the vehicle was in motion). My solution: Use the high one and hit the overrride switch to manually turn on the fan as soon as I brought the vehicle to a full stop. Result: A temp gauge that stayed at a happy midpoint all the time, just like the current "fake" gauges do.

-Uwe-

Sorry, noob question, but where would one find the magic green wire as to add the aforementioned switch?
Thanks!

nobodyhome1313 said:

Sorry, noob question, but where would one find the magic green wire as to add the aforementioned switch?
Thanks!

Click to expand...

Using the wiring diagram for whatever car you've got.

-Uwe-

Uwe said:

Using the wiring diagram for whatever car you've got.

-Uwe-

Click to expand...

Thanks, but the diagram doesn't show where physical wires are located, only how they are connected and to what. Was hoping someone who did this mod could share the specifics.

Thanks again!

You'll need to remove the rear seat and trim from the RH side of the car, this will expose all of the gubbings, the wire is connected to a block connector coming from the F171 switch.

It'll be obvious when you've got the trim off.

Outstanding, that's what i was looking for, thank you very much and sorry for such a silly question, brand new at this car. I'll get a pin out for that connector and diagram/ document this mod.
Sounds like i can do this along with the rear window track on that side... Bonus!