Weak A/C blower
 

I know my A/C could be a bit colder, and not sure if I can do all work needed myself to fix completly this a/c; ('85 300D-T);
It is charged, and holding freon I added. so it shouldn't be leaking...

But what part is it that could be bad if the a/c just doesn't blow strong enough???

So you are just referring to air blowing...without respect to the temperature of it ?
Check the electrical connections to the blower.
Check the condition of the fuse... take it out and clean it in case it has some corrosion...
It might need new brushes or bearings.

The other possibility is that your fins on the upstream side of the evaporator are clogged by 20 years accumulation of stuff in the air...
See Dmorrison's post about cleaning his evaporator... they can easily have more than 50 percent blocked...
A clue would be if you feel that the heater setting gives you more total air... assuming that your heater core is not also clogged... LOL

The heater I never tried...but the defroster always blows strong...and alway hot???
The fuses are clean and new...
Any pics anywhere on location of the blower???
How do I check fins of evaporator??
How would I know if the blower needs new bearings or brushes??
Thanks;
(I'l re-check DMorrison's link.
AA

Your AC and Heater use the same fan... only a flap changes the air flow. Try the heater to see if you get more air that way... which might point to the fins on the evaporator...
Yes, check out Dmorrison's thread... very good..
there should be some good threads in the archives about fixing the fan.. several have renewed the bearings... very cheap... suggest you do that if you take it out just on principle...
Blower should be directly above the passengers ankles..or close to that...

leatherman
 

Thanks, so far so good

Now Dmorrisons link is extremly complex for me so far...
I will check heater soon for blowing strenght.
I will find the blower in AM; WHo repairs bearings ; me or a shop?
Where is the evaporator located? Is it visible easy to get at??
When I find it I guess I'm just looking for dirty stuff to clean up???Right?
Thank you vvmuch!

"I will find the blower in AM; WHo repairs bearings ; me or a shop?"
You should be able to do it yourself... everything was posted by someone.. including the parts number for the bearings.. also , JimSmith talked about this I think.. probably inside the thread where the guy did new bearings for less than $5 ....

"Now Dmorrisons link is extremly complex for me so far..."

The evaporator is in a very bad position for access.... I am still mulling over my ' attack' on mine.... dropping the blower, making sure the flap is in the correct position and then getting cleaner spray to it.. while making sure the drain tube is clean and open... If you figure out how to clean the Evap fins be sure to post it SOON.... then I could quit Mulling about it...

----------
not the final word... but this one is funny..

http://www.peachparts.com/shopforum/diesel-discussion/86141-bird-dash.html?highlight=blower+bearings

this one is funny too...

http://www.peachparts.com/shopforum/diesel-discussion/99162-240d-acting-up.html?highlight=blower+bearing

OK,,, these are better...

http://www.peachparts.com/shopforum/diesel-discussion/42145-fixed-blower-motor-%246-03-a.html?highlight=fixed+blower

http://www.peachparts.com/shopforum/diesel-discussion/67842-fixed-blower.html?highlight=fixed+blower

The lack of flow may be due to vacuum elements not opeing and closing properly. This is a common problem and can be fixed

Check the flow coming out of your vents. It should be as per the following.

Check your fan first.

Top fan button max speed.
Middle fan button next speed down. ( it will be speed 5 of 2-5)
Bottom button speed 1. Lowest speed.

Set you AC to Full cold on the dial and max fan speed.

The horizontal buttons, I will number 1-5. Left to right

Push #5. The AC should be off
Push #4. The fan should come on. The outside air will be blown thru the center dash round vents only. All 4 ( 2 center and the drivers and passengers. ONLY
Push #3. Now the air will be the same as in #4 above but the compressor will turn on and the air will be cooled.
Push #4. Now the air volume will decrease not due to the fan changeing speed but due to the fresh air flap closing.
Push #5. Now the round vents will close. The defrost will open and all other vents close. The air will initially be cold then become warm. You get both AC and full heat in defrost.

IF ANY of the other vents are open and don't follow the list above. You have a vacuum element that is probably leaking.

A leaking element is rather common on a 20-25 year old car.

The fan location is very easy to get to. Just above the passengers feet is its location.
Drop the under dash cover at the passenger side and you will see it. 3 bolts and a wire to remove it.

Dave

Cool
 

DMorrison thanks;

per leathermng, I checked to see if heat and a/c were same strength. They are.
Now; my center vents recieve almost no air flow; I get a/c and vent(button 2) from corner vents only.
(All buttons operate as should..)
Also my blower is pretty loud on high; and while this is my 1st old MB; it sounds like there should be alot stronger flow....so my guess from the sound is that the blower is alright...Also the defrost blows fairly strong....
So if thats the case...then where to I find the leaking vacuum element? And tell if it's leaking? and repair or replace??

thanks agin'

" my center vents recieve almost no air flow"

This does not tell you anything yet.... the Climate control on these cars is complicated... you need to search for more info to sort this out... the two center vents are properly on or off with certain conditions... this should be in the archives somewhere... but I don't know how to find it.. aside from a lot of reading... maybe someone will speak up who knows offhand...

I don't know any more because my 1980 has the type one ( very simple ) compared to the type 11 and 111....

Again refer to my post above.
Place the fan on high. And leave it there
Push button 1 (defrost) the defrost vents should open and all other vents closed.
Push button #2 Now defroster vents should be closed and ONLY the center vents will be operating.
Push button #3 Same as #2 but you will get an increase in flow.
Push button #4 and it is the same as #3 but the compressor will turn off and the air temp will turn to ambient temperature.

So with button 2,3 and 4 only the round vent (4 total) will blow air and NO OTHER. when pushing #1 all vents will close except the 2 defroster vents.

This is for AC max cold only. Asking for heat does a variety of other thing.
But this test will determine if the elements are working correctly.

One last test, is to place the temperature dial to a warm setting. The only vents open now are the floor vents and the outside round vents. (drivers side and passenger side). All others are closed

The comment that your center vents receive almost no air indicates that either the center vent vacuum element is bad or the airswitch that control it. To determine this you will have to remove the center console panel where the AC control buttons are mounted and test the elements with a Mityvac as well as test the airswitches to see if they are working correctly.

It does sound like the center vent element is bad.

Dave