ive been so annoyed by this issue for more than a year now, when i bought it(over a year ago), heat and AC worked great. i dont have a manual so i dont know all the settings but it did w/e i wanted it to and worked for months, right before the winter it just stops, no blower. all my switches(US), would make loud noises when pressed, which led me to believe the CCU was still in working order.

while it started to get warm outside around srping time i would still leave the defrost button on because at a speed the hot air would come through for the cold mornings. in the middle of the day, the third time i started it, the blower motor works 100% again, totally random.

works for another two months, then take a guess what happens. now im stuck before another winter, i refuse to go without it. i have tested the blower with my battery charger, worked perfect, got another CCU from a junker, still makes the same hisses and whines when u press the buttons, no hot or cold air. any ideas? im really close to taking it to someone...

-1981 280CE US

I can't offer the answer you are seeking, but I can offer a resolution to your problem once and for all. I am guessing you have a climate control system.

One of the 1st things I did after buying my '77 280E in 1990, was to take out the entire CC system - the worst idea Mercedes has ever had - and replace it with a manual control from a 240D from the same year. This gave me total control of the heater/AC - and it always works! You could do the same with your '81 280CE. You do, however, have to replace the heater box and evaporator along with the control panel, plus change the heater hoses and diverter valve. To keep it simple, I used a thermostat from a 114 car, as suggested by a mechanic. It's a lot of work, but I would do it again in a NY minute!

Good hunting at the junk-yard and happy motoring!

i love my car. but i dont stalk it.....

i just replaced the water pump and all lower rad. hoses, i almost drowned going in the deep end of that. not sure i would be able to breathe seeing my whole interior in my garage.

could it be that the CCU still is able to open the vents and just not switch on the blower? or do the ones that need resoldering just not work completely?

bump,

I dont know your car model well but I do know that intermittent blower operation can be related to intermittency in the ignition switch. On my 87, 260E, the power for the blower comes straight from the ignition swicth and the contacts either get burnt internally or sometimes you just have loose connections on the outside. So please check this before going downstream to either the blower motor or the CCU. Also blower motors take a lot of current and so the fuse is also special, atleast in my 87 260E, and it develops hairline cracks that can cause intermittency.

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Saumil S. Patel

top, resoldering had no effect. has anyone else rewired the blower from the ignition? how much of the dash would need to be apart?

while working on my audio this past weekend, i did find a connection that was just sitting there it was hanging about a foot down from the driver leg panel and it started from what felt like the ignition. its not long enough to make it to the blower(the blower is plugged in obviously anyways). and my heat/ac has worked with this cable off...no clue what to do with it, it had a part # but i think it was for the connection clip.

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So the issue is that while the flaps seem to move, you have no blower in any position, including Defrost (button on the left)?

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

yes i still use the defrost button since when you get moving the hot air does come through the vents by itself. and pressing the off button closes them, for some reason the ac doesnt work the same way.

i have pressed every combination of temp/fan speed and switches, nothing at any speed

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Well, since you have no fan on any setting, I would suspect the blower regulator. It's a 12-pin black box with "ears" on either side. I don't know where it is on your car exactly, but you should be able to find a picture on one of the parts web sites.

I have the same sort of problem on my 560. I only have full heat and defrost air direction, but I can control the fan speed.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

only two i found on ********:

[IMG]https://www.***************/secure/PartImages/0008350157.jpg[/IMG]

climate control amplifier?? or,

[IMG]https://www.***************/secure/PartImages/0008221003X.jpg[/IMG]

AC control unit/ switching unit

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Actually, I was referring to this one - "blower regulator."

http://catalog.worldpac.com/buymb/022406/quote.jsp?header=http://www.***************/header.txt&footer=http://www.***************/footer.txt&partner=buymb&year=1981&product=R2022-11843&application=000359952&clientid=buymbparts&cookieid=22U15ESAM27F0ZDJVF&baseurl=http://www.***************/

But please don't take my word for this. The whole system is one big expensive black box. I would hate to see you spend a couple of hundred bucks on an unnecessary part. I would suggest getting the schematic and seeing if your dash unit is sending a signal to the blower control.

I have the amplifier shown as a part in my 560 as well, but it doesn't seem to be on any of the schematics. The older cars with the servos used this part, though.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe