Where, exactly does a typical engine block heater plug in?
 

And don't say 'the wall'!
My 82 300d supposedly has an engine block heater. These past few weeks have been pretty cold, so I thought I would help the engine and plug it in overnight. Last night, I did just that, but nothing warmed up. Upon further investigation under the front bumper (where the heater cord is located), I found that both sides of the plug were free. I can't seem to find where the engine block heater plugs in. Can you help me, please?

Not sure exactly where the Block Heater would be located on a 300D but it will be in place of one of the 'Frost' Plugs on the side of the Engine Block.
On my SDL it is on the exhaust side about half-way along the block.

I'm still poking around and can't find anything.
The cord itself looks like an ordinary extension cord-is this what was used for an engine block heater? It's pretty old looking as well.

yes
 

it is a three wire flat heavy cord. the block heater will be in the pass side low centerish. it will have a three prong electrical male prongy thing that your cord will plug into.

if your motor has been replaced, you might have a cord and no heater in the block.

tom w

The block heater is located on the passenger side of the engine, about three inches above the very forward end of the starter. It's difficult to see it and even more difficult to reach up there and plug in the cord. Get a lot of light from underneath. Jack the vehicle up and put it on jackstands. You'll need to get way underneath it, between the wheels.

The freeze out plug block heater is obscured by the turbo. You can visualize it from top side, looking toward the block through the turbo and pipes.

Interesting......... My block heater is located on the drivers side of the engine.......

http://www.w123-world.org/showthread.php?t=15

If you look at the right side cross section (looking striaght on) there is a bump out at about 9 O'clock along the block near the rings on the pistion. That is close to the factory freez out plug heater. If you remove the air filter and get a flash light, it's a bit eaiser to see.
I'm a bit confused bt your sig though (300DT)... do you have a wagon (300TD)
or a 123 sedan (300D)?

I have a 123 sedan.

There is a plug-like apparatus just forward and three inches up from the starter, but it is a 2 pin like connection-not the traditional 3 prong plug in. I'll check the other locations posted here for this elusive item.

Btw, that url is a dead link on my machine.

Located pass side near starter. If you dont already have one there then get out the blue torch or check out the pictorial.

http://dieselgiant.com/mercedesblockheaterinstall.htm

Awesome pictorial!!! I may just have to get me one of those deals.

How come all the conflicting locations on the stock engine block heater?

Mercedes only put block heater in one place on the 617, so its anybodys guess.

Does anyone know what type of cord would plug into this pin-like plug I've described?

use the Fastlane search feature. $15
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1OM0QSL461OM0QSL45&year=1984&make=MB&model=300-TDT-001&category=All&part=Block+Heater+Cord