'75 911S Counter switch instalation

[Attylla]

Hello Pelicans

Hope You're all enjoying the summer.
I am working on the frankestein as I now call the 911S I bought recently.
Everything on that car seems to be from a different MY

Now I discovered someone decided to replace the original speedometer (mechanical) and replaced it with later electric unit.

I am desperately trying to bring everything back to original specification but I encountered series of problems the most urgent at the moment being identifying original placement of the MPH Counter Switch on the car.
No 1 on the attached picture.



I am also missing the drive shaft 1m long 91164151500 No 8 on the attached picture.

Could someone advice where exactly is the Counter Switch Unit mounted?
Maybe someone has and doesn't need the drive shaft Speedo to CS???

Best Regards
Marcin

[crashr]

Hi Marcin,

It is mounted right behind the speedo. If you pull out the speedo from the dash you should see it just slightly back down and to the left. I don't think you need this, as my understanding is that it was simply used to turn on the EGR light at a certain mileage. I replaced mine with a mechanical cable that went right between my speedo and transmission.

[Attylla]

Thank You crashr

In my car it's actually right where You described it but it was hard for me to believe it could be the original location since the distance between the switch and speedo is maybe 20cm and the original cable should be 1 meter long. That's a lot of cable to squeeze in that space for no reason

Would You like to get rid of Your old cable since You don't use it anymore?

Best Regards from Poland
Marcin

[crashr]

Let me see if I can find it and I will let you know. I can tell you the cable is not 1m long, more like 15cm. In fact it is a very tight fit in there.

[drtyler]

First, don't be so quick to remove the digital speedometer. If it works right, I would leave it be. The cables can fail. I think the electronic speedometers are more reliable.

If digital, does it have a newer transmission (1976 and newer)? Does your transmission have the fittings for the mechanical speedometer cables?

You could also use a 1974 cable with is a bit longer and avoids using the mileage counter. My '75 has the mileage counter, and the short cable makes it difficult to remove the speedometer. You have to first remove the clock, unscrew the short cable from speedo to counter, then remove speedometer.

My next project is removing the counter and installing the longer '74 cable. The EGR system is no longer on my car, and it doesn't make sense to add it back either.

Originally Posted by Attylla

Hello Pelicans

Hope You're all enjoying the summer.
I am working on the frankestein as I now call the 911S I bought recently.
Everything on that car seems to be from a different MY

Now I discovered someone decided to replace the original speedometer (mechanical) and replaced it with later electric unit.

I am desperately trying to bring everything back to original specification but I encountered series of problems the most urgent at the moment being identifying original placement of the MPH Counter Switch on the car.
No 1 on the attached picture.



I am also missing the drive shaft 1m long 91164151500 No 8 on the attached picture.

Could someone advice where exactly is the Counter Switch Unit mounted?
Maybe someone has and doesn't need the drive shaft Speedo to CS???

Best Regards
Marcin

[Attylla]

Thanks for all the good hints.
As soon as I'm back at the garage I'll check the transmission.
Cable spec is defined in mm and not cm as I thought so It's 10cm rather than 1meter

My priority is originality so even if electronic is more reliable I'll still be bringing all back to original setup.