996 starting problem.

Does anybody here have experience with (and perhaps solution for) following starting problem on a 1999 (?) 996 Carrera with manual trans :
Occasionally, the car will not start during normal attempt unless the clutch is "pumped" few times.
I assume there's a neutral safety switch to prevent starting without depressing the clutch, but is it "mechanical" or "hydraulic" (or is the clutch even operated hydraulically) ?
Where would such switch be located ?
Could anybody be willing to provide me with good, clear image of a wiring diagram for this circuit ?

I'm more accustomed to restore and service (carbureted) classic and vintage vehicles, but this car belongs to good friend who prefers my repairs/services on all of his cars, so I'm just trying to prepare for diagnostics before it gets to my shop next week.

Thanks in advance,
Timo

 

Thanks for quick answer.
So, basic mechanical (safety) switch connected to clutch pedal or it's support ? Well, that should make it (hopefully) easy to diagnose and service.
BTW, is the clutch movement in these cars transferred by mechanically (via cable ?) or hydraulically ?
Timo

 

Can any one confirm (or deny), whether this switch failure is common cause for the problem described above, since it unfortunately has not reoccurred in past couple of weeks ? Or should I look for some other possible common culprit ?
In general, I do not wish to arbitrarily replace components just to see if that would take care of things and owner wishes to have a peace of mind before taking the car on any lengthy trip.
Any experienced input would be greatly appreciated.
Thanks,
Timo

 

Thanks to all for their advise. Replacement of the (apparent) culprit switch was relatively easy and hopefully took care of this annoyingly inconsistent problem, which I was actually able to simulate in the shop, although also inconsistently. There are two switches linked to clutch pedal movement under the dash, this one (micro switch type with a lever, part # 997 613 109 02) for the starter safety circuit and another (plunger type) is a cut-off for c/c circuit. Interestingly, when asked if this is common problem, the parts manager at the local dealership answered very diplomatically "Well, we sell a lot of them"
Timo