280SL Euro AC blower is weak - PeachParts Mercedes-Benz Forum

desert · #1 06-02-2011, 02:08 PM

My 85 280SL Euro has the dual temp control wheels on the dash,I've replaced the AC compressor which was leaking, the system is topped off with R12, everything is working as it should but I am just not getting enough air from the blower through the dash vents even at it's top speed.It has about half or less the blower power on my 04 E320 wagon. Has anyone found a replacement blower motor that can really blast the cold air from SL dash vents? If so, can your give me a source and advise the difficulty in replacing it? Thanks, Desert

RadioTek · #2 06-03-2011, 04:59 PM

I seem to remember something about a foam under the dash that pulls cabin air into a sensor in the aircon system. That tube is said to fall apart due to age, and cause probelms with the system, because it would pull air from under the dash into the sensor. If there's a bit of an air leak under there, the cooled air would give false indications of the cabin already being cool.

just an idea,
Scott

desert · #3 06-04-2011, 10:13 AM

I don't think that's the problem since all the vents under the dash were checked, cleaned and re-attached just a few years ago. I think the problem is that the blower motor is just not powerful enough to push a higher volume of air through the vents. Maybe because the car is a European model where temps are a lot less than here ( Arizona) they didn't feel is was necessary to install a high volume powerful blower motor. All the American cars I have had ( last 30 yerars) and recient Mercedes wagons have put out twice the volume of air as this SL. I'm still interested if anyone has replaced the original blower motor with sonething stronger....Thanks Desert

rowdie · #4 06-04-2011, 12:06 PM

The foam referred to is a foam hose leading from the cabin air sensor on the dash. Easy enough to confirm it is there by removing the glovebox. US models and ROTW models have the same blower motors.
You may not be getting top speed from yours. No knowledge of replacement motors.

RadioTek · #5 06-04-2011, 06:55 PM

How does the blower motor sound? Does it sound like it's running full speed? Are there any odd noises, such as squealing or chirping?

There is a resistor pack attached to the cable for the motor that has a bi-metallic strip to protect from overload, that some people have has to readjust to get things going properly.

Could the blower motor switch be part of the problem?

Depending on year and options, there are vacuum powered flaps that direct the air flow, could one of those be hung up?

Just a few more ideas, not having the thing in front of me, that's all I can offer.

Where in Arizona are you? I'm in Glendale.

Scott

desert · #6 06-05-2011, 02:16 PM

The blower motor sounds normal, the car only has 60K on it and not driven that often so the motor hasn't been used that much that it would be worn from use. It is a 4 speed rotary switch which feels normal and at top speed it sounds normal and probably is factory normal, it just doesen't put out enough air in my opinion. Guess I could take it to MB and get their opinion but since this is a Euro model they don't seem very familiar with it either. I don't think any of the flaps are hanging up, good air is coming through the correct outlets but not at the volume or force I would like. I'll see if I can find the resister pack you are refering to. We live in Saddlebrooke, outside of Tucson, about 5 degrees cooler than Tucson but I think we'll hit 100 plus today. Think you are hotter up your way....Thanks Desert

79Mercy · #7 06-05-2011, 05:23 PM

Take the blower out and inspect. Believe it or not i have found rodent nests in the evaporator case in cars that have been sitting around for many years. Take the blower out and clean the evap of anything that could be blocking air flow.

Also check for voltage at the blower, are you getting a full 12+V to the blower?