My car is an 85 300d turbo.
A couple owners ago, someone unhooked the RPM sensor.

I'm curious if it has anything to do with the CALI system on my
car that is bypassed, and if rehooking it could cause a problem.

Also, When reattaching the parts for the RPM sensor (they were in a bag in the trunk) I didn't know what number ports to put the loose wires into...

Also, I belive I am missing a top piece, as there is nothing to pop in that connects the connections in the unit...

Here are a couple pics of what it looks like now.

There is supposed to be a unit with plugs that fits in that top cap, yes?



Seeing that the wires that go into the numbered port semi-circle wernt connecting to anything anyhow, I just put them in wherever for now, at 2 & 6.



How do I find out the correct ports for those wires?

__________________
OBK #32
1985 300D Turbo (15 gal Greasecar kit installed)
(258,900+mi.) Thanks- Tachometer Fixed. Middle Vents Fixed. Transmission- 1000% better shifting.
Vac leaks- Fixed, Brakes replaced, Steering Box replaced, .... Information Rules.

that is the can for diagnostic readings at the factory. the 85 uses a different method for RPM sensoring than the previous years. It's on the flywheel. the most likely culprit for your tach not working is somebody put in a tach from an older model when the speedometer went out...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Note the short screw on cap. There are no connections there. As vstech mentioned, different system on newer 123's. My CD has the same set up. The SD has an amp cap on those pics. I understand the signal comes from tranny somewhere. And you do need correct gauge. Only way to tell is to pull, look for a three male prong deal thing on back. There is also a year rubber stamped on back, may even be able to read. I have pics of both, have yet to be able to post here, can regular e-mail. The early models had a two pronger.

__________________
83 SD

84 CD