If you are using the original VW / Hella vacuum cruise control system which VW used in the T25 / T3 / Vanagon models, it has to use VW switch (811 907 343 B) because it is both a switch and a vacuum valve, as required by that system. However, most other OEM cruise control systems and ‘drive by wire’ throttle systems require pedal switches which are not compatible with 811 907 343 B, typically because one or both of them needs to have normally open and normally closed contacts, not just normally open.
When using cruise control from Subaru (or a later VW engine with engine management – i.e. not the Hella cruise control originally fitted to the T25 / T3 / Vanagon) or an engine with a ‘drive by wire’ throttle, you need brake and clutch pedal switches for these systems to work safely. You can use the Subaru pedal switches if the donor car was manual, or the Subaru brake pedal switch plus another switch (if the donor was auto), or with some of the inline VW engines, their original switches don’t lend themselves to easy use with the T25 / T3 / pedals. The solution often used to be to use VW switch 811 907 343 B for the clutch pedal (connecting only it’s switch, not its vacuum valve). However, they’re no as reasonably priced anymore, and are not suitable for a lot of brake pedal applications (including all Subaru) anyway.
Pedal switch set – T25 / T3 / Vanagon brake pedal (part no. 800-00069)
Pedal switch set – T25 / T3 / Vanagon clutch pedal (part no. 800-00068)
Functionally identical to a Subaru brake pedal switch, but much more reasonably priced, our pedal switches comes with a pedal switch bracket, lock nuts, self tapping screws and a ‘pedal arm widening’ clip, so fit just the same as the VW switches. They can be used for either brake or clutch pedals in all applications which require only electrical switching (i.e. not also vacuum valves). They contain two pairs of contacts – one normally open and one normally closed. It is critical that you both identify which one(s) your application needs and connect them correctly if wiring them yourself. If we’re doing your wiring work for either Subaru cable throttle cruise control or ‘drive by wire’ engine management, and you don’t have suitable pedal switches, we fit these.
Note, these switches are for for inside use, in the dry only. They are not remotely suitable for use under the floor, outside, if you are attempting to fit cruise control or a drive by wire throttle engine into a bay window or a split screen bus. Pedal switches cannot neatly be installed inside a bay window or a split screen bus due their their unusual pedal arrangement where most of it is outside, under the floor. They require IP67 or better waterproof pedal switches outside, which is not that easy to achieve (at least not as a sellable product, given that there are 6 different pedal arrangements just in bay window buses).
Pedal return spring note:
Note – your pedal return springs need to be in good condition to use pedal switches. They must positively pull the pedals up against their stops for the switches to work reliably. This is a common cause of cruise control problems in the T25 / T3 / Vanagon, as the clutch pedal springs seem to often stretch slightly, leaving them with a bit of slack at the top of their travel (i.e. not pulling the pedal against its stop at all), so preventing the switches operating correctly. If you have a pedal return spring which has stretched, you can’t adjust this out – the only fix is replacing it with a good spring.
Adjusting pedal switches
First make sure your pedal return spring had not stretched, as described above. If it has, you’ won’t be able to set the pedal switch until you’ve replaced the spring. Then adjust the switch until the plunger is pressed in and the threaded switch body is touching the pedal widening clip (our switches or Subaru switches, or until the plunger touches the switch body with 811 907 343 B). Then back the switch off 1mm (just under one turn with our switches or Subaru switches, 2/3 of a turn (240o) with 811 907 343 B) and tighten the locknut