A/C issue
Thread Starter
Member
Joined: Apr 2012
Posts: 178
Likes: 1
From: So California
1999 C43
A/C issue
I live in a desert climate, use my air conditioning year round & its always been very reliable but recently developed an issue. When starting up after a stop the blower speed will drop to almost nothing for about 8-10 seconds then
it comes on full blast. This usually only occurs when outside air temp is 90 plus. It sounds like it is linked to manifold vacuum but that doesn't make much sense.
What do you think?
it comes on full blast. This usually only occurs when outside air temp is 90 plus. It sounds like it is linked to manifold vacuum but that doesn't make much sense.
What do you think?
Thread Starter
Member
Joined: Apr 2012
Posts: 178
Likes: 1
From: So California
1999 C43
I understand what you are saying but I do not set the A/C on 'AUTO' Stopping or accelerating should not affect the evaporator blower speed. Have not had this issue for 14 yrs of ownership.
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From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Did you diagnose the car..?,
you may have bad Evap. temp. sensor, or not enough gas..??,,
also, did you check the condenser fans, if they working or not..???
-;ZAYED;-
you may have bad Evap. temp. sensor, or not enough gas..??,,
also, did you check the condenser fans, if they working or not..???
-;ZAYED;-
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Joined: Mar 2005
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From: America
1999 C43 AMG, 2005 E55 Wagon
I think I have the same issue. It's not that the blower slows down when accelerating, it's that the air gets ducted elsewhere under acceleration. About 8 seconds after I let off the throttle it will redirect the air to the main vents and I feel it blast again.
I agree its vacuum related. I've done no digging, I rarely drive my w202 right now.
I agree its vacuum related. I've done no digging, I rarely drive my w202 right now.
Thread Starter
Member
Joined: Apr 2012
Posts: 178
Likes: 1
From: So California
1999 C43
Sulaco,
I think we are on the same page, I am going to try switching some of the vent positions on & off, they are all vacuum controlled. I had switched it to auto control and back off the other day and I think that improved the issue.
If I find a fix I'll let you know.With these 20yr old cars it's something new all the time.
I think we are on the same page, I am going to try switching some of the vent positions on & off, they are all vacuum controlled. I had switched it to auto control and back off the other day and I think that improved the issue.
If I find a fix I'll let you know.With these 20yr old cars it's something new all the time.
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Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
Sulaco,
I think we are on the same page, I am going to try switching some of the vent positions on & off, they are all vacuum controlled. I had switched it to auto control and back off the other day and I think that improved the issue.
If I find a fix I'll let you know.With these 20yr old cars it's something new all the time.
I think we are on the same page, I am going to try switching some of the vent positions on & off, they are all vacuum controlled. I had switched it to auto control and back off the other day and I think that improved the issue.
If I find a fix I'll let you know.With these 20yr old cars it's something new all the time.
Thread Starter
Member
Joined: Apr 2012
Posts: 178
Likes: 1
From: So California
1999 C43
Sulaco,
Try this, once you are up & running switch the blower speed up to highest setting for 5 seconds, then back to normal 2 or 3 on blower speed, maybe do this twice. It corrected my problem, hopefully for good.
Try this, once you are up & running switch the blower speed up to highest setting for 5 seconds, then back to normal 2 or 3 on blower speed, maybe do this twice. It corrected my problem, hopefully for good.
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1999 C43 AMG, 2005 E55 Wagon
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1995 E420, 1998 E300TD, 2002 CL230K 6spd, 2002 CL230K auto, 2002 CL280T VR6 Project, 2001 A6 2.7T
I live in a desert climate, use my air conditioning year round & its always been very reliable but recently developed an issue. When starting up after a stop the blower speed will drop to almost nothing for about 8-10 seconds then
it comes on full blast. This usually only occurs when outside air temp is 90 plus. It sounds like it is linked to manifold vacuum but that doesn't make much sense.
What do you think?
it comes on full blast. This usually only occurs when outside air temp is 90 plus. It sounds like it is linked to manifold vacuum but that doesn't make much sense.
What do you think?
If this is the case then you may have an "air distribution" problem and , if memory serves me right, there is a vacuum distribution block under the hood in the right rear module box compartment area. It should be black in color and have several vacuum lines connected to it. The block has a steel ball pressed into one end of it and this is usually where it cracks open and leaks off the vacuum.
This is easy to check without connecting any test equipment to the vehicle.
Thread Starter
Member
Joined: Apr 2012
Posts: 178
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From: So California
1999 C43
Not sure if we are talking about the same car but on my C43 I do not see anything that resembles a distribution block or anything with vacuum lines attached to it under
the hood.
the hood.
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
There is one somewhere as per diagram attached. If I recall it's somewhere behind the glove compartment once you have removed the thing from the dash area.
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