Hello, I have a 1987 US spec Merc. 190E, with electric heater controls. Ive owned it for roughly 6 years, It has always had its little issues but now the heater blower will just turn on full throttle while in the off position then turn back off, then turn back on then back off and so forth. It gets pretty annoying while driving down the road. Also It is stuck on hot. I can select cool on the dial but it never turns cool.

Could this all be linked to my push button control unit in the dash?

thanks to all that can point me in the right direction

David Lee Portland Or.
1987 300D
1987 190E 2.3
1984 230E Euro

I would guess the Blower motor regulator is damaged.

http://www.peachparts.com/shopforum/diy-links-parts-category/212324-blower-motor-links-page.html

http://www.peachparts.com/shopforum/general-information/281139-w210-cheap-blower-regulator.html

.

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My push button module has a defrost switch on it that runs the fan at high speed when I push the button. As for the temp control being unresponsive, I would suspect bad / dirty switches in the control. If you have one available, I'd try swapping it out for a spare.

Mine didnt work. I cleaned 25 years of crud out of those switches, replaced the electrolytic capacitors on the circuit board, and mine mysteriously came back to life. Electrolytic capacitors dry out over time, and go bad.

Best of luck getting your car to do as you want. I sure can't!

Bruce

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.

As far as always having heat the 190's have a vacuum operated valve that opens for heat and closes when you are wanting cooler air stopping the flow of coolant thru the heater core. These are prone to go bad and won't hold vac allowing you not to be able to control heat. It is on the passenger side of the firewall you have to pop out the plastic screen that is at the base of the windshield and the just look for a vac line running to a vac pod. Apply vac and see if it holds.

OK. So I replaced the push button control unit and the seems to have fixed that problem. my heater still doesnt know what vent and floor controls are but at least it only turns on when I ask it to. I guess if i could only pick one outlet it would be defrost so im not sitting too bad, also the heater still only wants to blow out hot air no matter where the adjuster dial is set. Granted i just installed the new control unit, maybe the old one was completely fried and it just needs a little electric currant running through it again, and it might start working again. My heater fan speed switch is also broke and I cant figure out how to get it out to replace it

The Members of this forum are Great, thanks for all the tips and advise
Every bit of info I gain is greatly appreciated
Thank you again

David Lee Portland OR
87 300D
87 190E 2.3
84 230E Euro

If you are getting defrost vents, you have a vacuum leak somewhere. The vacuum comes from the manifold, and up to a green (?) one-way valve attached to a vacuum tank. This valve often goes bad. It's close to your fuse center.

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.

They are electric.

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The switches are electric. The doors and flaps are vacuum operated. If theres no vacuum, the system defaults to defrost.

The valve in the heater water line closes when vacuum is applied. I know from experience about this valve.

There is an elaborate electromagnetic vacuum valve set-up under the glove box. This controls your heater functions upon commands from the thermostat.

Mine had a crack in a vacuum line that caused the system to switch to defrost when I was climbing a steep hill, and switch back to normal after I let off the gas again.

__________________
My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.

Thanks Guys

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07 E350 sport Wife's Daily
01 E320 sport My Daily
00 C230 Kompressor Our back up (new Arrival)

87 300D Turbo my Daily for 8 yrs. Selling to neighbor

82 GMC Jimmy (K5) 6.2 Diesel (my Wheeler)
73 Roadrunner 340ci My very first car, still own it

Ill check that, sounds simple enough. right?

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Live simply so others can simply live



07 E350 sport Wife's Daily
01 E320 sport My Daily
00 C230 Kompressor Our back up (new Arrival)

87 300D Turbo my Daily for 8 yrs. Selling to neighbor

82 GMC Jimmy (K5) 6.2 Diesel (my Wheeler)
73 Roadrunner 340ci My very first car, still own it