1982 300d

when i push any of my heater buttons...nothing ever really happens.
high or low.
sometimes when i first start my car the fan comes on if the defrost button is already pushed in. i ordered a mono valve already. question is. shouldn't the fan come on either way if i push the buttons..

There might be a delay in the fan blowing full tilt but it should come on immediately. If it's more likely to come on on max than other settings, I'd check for worn brushes and bearings. I don't think the monovalve has anything to do with fan behavior.

Sixto
87 300D

so if i click the ccu buttons...it should be either high or low fan speed corrects...i get nothing....i know heat wont come out til its warm...but nothing happens

Fan speed is determined by the CCU or the blower controller (in some cars the blower controller is separate) when the fan is set to automatic, except for defrost which always blows on max. If the fan is set to min or max, the CCU will not override except for defrost. Some cars like my '87 have a delay so you don't get blasted by hot air from a heat soaked heater core on a hot day, but the delay isn't even 10 seconds. The fan comes on slowly then builds to whatever speed the CCU determines appropriate.

Follow this guide to inspect the blower brushes - PeachPartsWiki: Replacing the Blower Motor Brushes . If there's axial play in the blower motor, don't bother with brushes because the bearings are bad.

Sixto
87 300D

On your 1982 the blower controller is located behind the glove box. It is black and mounted to a metal bracket just below the windshield to the far right. It may be a little hard to see as there are quite a few wires in thus area. It has a black plug in. To the left is the silver HVAC controller.

ok fan out...how do i get the big white fan off to get to the brushes...
when i pushed on the center fan post when it was in the car...the fan would activate.

never mind...figured it put...
rookie here

Sounds like bad bearings shifting where the brushes make contact on the armature(?). Replace the blower motor so you can find other problems with the ACC

Sixto
87 300D

FIXED.
cleaned all the carbon off the brushes.
and the part the brushes sit on
everything is working.
well defrost..and the next two buttons next to it..
i have it on auto now to see if it shuts off.


thanx for all the help.
im about to take a 400mile trip..will be nice to have heat.

wont be tkaing that 400 mile trip anytime soon.
just noticed my new used oil cooler is leaking.
just installed it a month ago
was supposedly tested and in know good working order

grrrrrrr
guess il have to get a new behr one


i hate fleabay.

You might have better luck from a member seller in the parts forum... and still make your trip.

Sixto
87 300D

i hear ya. i bought it before i joined here.
poop