Gentlemen,
My heat will not turn off. I have read everything I can find on the hvac system, but most of it relates to Nth American models and mine is an import from Japan, 124193 603960 so has the semi-auto hvac system like the aussies. Can anyone send me or link me to a schematic of the electrical and coolant circuits, and where is the control module? I can shut down the air circulation by turning the fan dial to O, but then of course the AC doesn't work. With the fan dial on anything other than O and the temp dials on blue, the coolant is still flowing and baking the car occupants. It's the opposite of the usual problem we have here in Canada. Any diagnosis info much appreciated!

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Newer style heater valve/pump in that first pic... just look for e300 info instead of the older model stuff. Pull it and test it (the two valves that cut off coolant flow). Or maybe just replace it, I saw one on an e420 in the junkyard the other day.

I pulled the valve and dismantled, and cleaned the crud out, but the coils tested at about 1.5ohms so I reckon they're toast, and no doubt all the rubber parts have deteriorated too. So I'm looking for a new one (gasp $500+) or a good s/h. Seems to me the rubber parts fail first, which allows coolant to invade the coils, which eventually locks up the whole shebang.
Thanks aaa, I'm looking.

Use the term "duovalve" when searching. The older cars used a "monovalve." Maybe you can find a used one somewhere instead of having to pay the dealer for a new one.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

wow, i didn't even know there WAS A '94 E300 TD
thought it was only 98-99, but i see yours looks like a Euro model

It's a Japanese model, imported to Canada last year, and i have ordered a new valve from Mercedes in Halifax, coming from Germany. $494 plus tax. The car is pristine, and I'd like to keep it that way, though this is a bit hit on the running cost budget!
Thanks to everyone for the advice.

To close this thread, I installed the new valve and everything works as it should. I stripped the old valve (curiosity is a very powerful thing!) and the diaphragm that is supposed to seal the valve pintles was destroyed, allowing coolant into the solenoids and seizing up the whole thing. I now have a nice little pump to play with on some future project.
Next job: the block heater install........

Wow that's a sweeeeeeet wagon!

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1981 300TD 4 speed manual
Euro bumpers, zender valance and skirts, H&R springs, billy HD's, leveled sls, real AMG Pentas 16x8 et11, vdo boost/egt gauges intergrated into ash tray, eurolights, led 3rd brake light

x 2. Did you import yourself or source with the of the JDM resellers here in Canada?

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- 2006 T1N 10 Passenger 2500 Sprinter- Family Hauler
- 1987 W124 TD Variant. Project.
- Plus several in "the works".

Thanks for all the nice comments.
I bought it from an Albanian living in Canmore, Alberta, whose previous life included importing cars from Germany to Albania. When he and his father moved to Canada, they continued the business but now from Japan to Vancouver. I've always wanted a diesel so it was an easy sell for him! The only mod needed to import into Canada was daytime running lights.
I have used the RIV program to import a motorcycle from the usa and found it fairly painless, as long as you follow ALL the instructions.

I am drooling. More pictures? Underhood?

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'86 300 SDL '83 300D Astral Silver/Blue
354k miles.. 326k miles..

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