There are 2 switches on the dryer on a 123.

The pressure switch is in the compressor circuit, it keeps you from frying the compressor if you have insufficient charge. The switch has large hex flats and does require evacuation to replace since it has to see the pressure of the refrigerant to work.

The temperature switch is threaded into the brass block on top of the dryer. This is the switch that triggers the fan. It has two quick disconnect terminals in line with the switch. A common DIY hack to have aux fan all the time is to unplug the switch and connect the two terminals together. This pulls in the fan relay anytime the key is on. The switch is simply threaded into a blind hole in the dryer (no connection to the refrigerant passages) since it only is sensing the temperature of the dryer body.

The temperature switch is cylindrical and if your dryer is stock the rear end of the switch is pointing straight at the radiator. It unscrews but as vstech and I found out it is easy to break. Phil has them.

Reminds me, I put mine back together with duct tape, and I need to replace mine. It works but I don't want to leave it like that.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

feel like sending me a reamer?

Sure, but I doubt it will make it by friday. Should I include an 80 amp strip fuse as well? I have 2 spares and already have one taped in the glove box as Charlie mentioned above.

It is easier to use the reamer if you pull the intake IMHO. I'm sure it can be done with it in place if you are patient though. It may take some cursing. BTW the nuts on the wires are captured on the 124.

PM or email me your address and I'll send it out.

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

After reading the above post on the cost of the 80 amp fuse, the dealer
will give you a good ream.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Yikes. i've not had that particular run in that bad... but I too have had to go back and repair other peoples repairs and put it back to factory. Redoing most of the fixes in the dash area was an absolute nightmare. Hopefully you dont find any more 'interesting' fixes

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

Oh boy, I've found some fun fixes..

I need to check the box that the head gasket came in and see if there is an intake gasket and gasket for the crossover tube.

and find a thread on removing the thing.

there should be a topic of the most creative fix we've found. I bet there is quite a few of them as sad as that is

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

A PO of my car apparently had an overheating problem in the past, because my auxiliary fan comes on whenever I turn the key in the ignition. Rewired it somehow, though I'm not sure if it's something I should worry about or not =P

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1983 240D, 272K+ miles (odo broke)

Most likely just connected the wires that go into the pressure sensor that has failed and does not activate the fan when the AC is in use. I need to replace my sensor as well but it involves evacuating the AC system I believe.

anyone have a link? I've been searching for about 20 minutes and nothing solid yet.

I did find a post by Bohdi about oil coming from the head bolt between cylinders 1 and 2. I have the same issue and hers was solved by a new intake gasket and valve cover gasket.

Two GP's being out is probably the only reason that 30A fuse lasted as long as it did....since 4GP's is about 35+ amps.

At least they used a fuse and not a piece of 12GA wire or something!

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Yep, better to use a fuse too small than a fuse to large in amps.

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)

My SD had a hitch on it when i first got it; didn't realize the PO just drilled holes in the bottom of the spare tire well to mount it :@

lets just say I've had several dozen used cars over the years... not to mention working in auto garages, and on customer cars in driveways for 30 years... VW beetles are the WORST for cheapscate engineering...


I can't type all the mess I"ve found...

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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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

worst one I found was bailing TWINE wrapped around the control arm to keep the wheel on, after the ball joint had failed...

I've found differentials packed with vasaline...

arrgh...

__________________
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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!