Today I'm working on my 83 300D, trying to figure out vacuum issues and why my transmission shifts rather hard. I'm testing all the various vacuum lines. The central locking system appears to have no leaks. If I manually apply vacuum to the system, I can make all the locks work with the key.

Now I'm getting ready to test the black line going to the tranny. I follow the line down to where it connects to the tranny, and I see this other wire just dangling. It has a 3-prong connector on it, so it looks rather important. Yet, I couldn't find a connection that would receive this 3-prong wire. So, I followed the wire back up along the firewall, and saw that the other end is connected to this grey box down in between the IP and the side of the engine where the glowplugs are (sorry I don't know all the terminology yet).

I'm attaching pictures of both the connected end of the wire and the 3-pronged end that I found dangling by the tranny. Can any tell me what the hell this thing is, what it's for, and what it is doing to my car by not being connected???


***EDIT*** On my first pic I accidently typed "Ignition Pump," obviously I meant "Injection Pump"

Attached Thumbnails

   

I think that is the temp sender on the engine. Does you dash gauge work?

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83 SD

84 CD

My temp sensor reads fine on the dash. I'm not so sure that's it?

So no one could name this part? What if I make it a contest?

Kickdown?

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1989 300E 144K