psparky

Hi folks, I found a disconnected connector on the 4000S quattro hanging down by the motor mount on drivers side. The connector has 2 wires, a brown and a brown/red. I looked thru my wiring diagram and it appears like it is for the upshift switch, my upshift light does not work, but I can not locate this switch, is it on the trans? or manifold? any help would be appreciated. thanks

Rogviler

There's a picture of it in another thread:

https://www.audiworld.com/forums/aud.../#post25182622

I've only seen one car with it working. I'm curious what goes bad in them and what it means to adjust them.

-Rog

psparky

Thanks Rog, but I searched that thread a couple of times and I don't see any picture of this switch, can you copy and paste in here, thanks

psparky

Rogviler

Right in the middle of the photo.

-Rog

psparky

Thanks Rog, but it is not there, can you tell me where the vacuum lines originate from and go to, it can't be very far away as the pigtail connect is just not that long, I have a picture but having trouble posting it, will keep trying, thanks

psparky

My car

psparky

Rog, good puzzle, in factory manual section 26.2 and 26.3 there are vacuum control lines and in appears like the vacuum switch is in the vacuum line that goes to the distributor vacuum advance/retard, make sense? Seems obvious to me now that someone removed the switch, the line goes from the distributor to the other side of the intake manifold, go figure

Rogviler

Yeah, you got it. I would guess it's a potential vacuum leak source and there's not a lot of info on them and their repair-ability (I would guess there's one or more seals inside that can fail), so I'd remove it too.

-Rog

Rogviler

Since I don't care anyway, I'm going to pull mine and do some exploratory surgery on it, see what it does and what could break inside.

-Rog

Erik Myers

Hey that's from my thread! It comes right out of the dizzy advance, if I recall correctly. By some miracle my shift light actually works, but who needs that when you wanna drive it like Hannu Mikkola? I say never shift unless your tach is hitting the bottom of the dash