E320 Heat problems
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SL55 AMG
E320 Heat problems
Hello,
I just bought an E320 Convertible with 108,000 miles on it. It looks like the car was neglected. Many things don't work. But all of the major things do work. Windows, engine, top, etc... haha.
The previous owner seemed too lazy to repair the car properly. The heater is wired to a switch that's located under the dash.
Here are the problems:
-Heater is stuck on defrost
-Regardless of hot or cool setting, it blows heat. Not warm air... HEAT.
-Hi/low/off does nothing, probably because its rigged to that switch?
I am aware there is a "switch board' for the vacuum-actuated heat controls on the passenger side, but I find it hard to believe all of them stopped functioning. I wonder if it's even getting power.
I popped the hood and did a basic inspection of the vacuum lines. I believe the heater vacuum lines are on the driver side. I saw 3 diaphragms that split off from one vacuum. They all looked to be in good shape. I also replaced some dry-rotted ends from under the intake manifold. I saw a blue vacuum line, a lighter blue, a red one, and an off white. Anyone know which line goes to what?
What's the first thing I should be checking?
Thank you.
-Todd
I just bought an E320 Convertible with 108,000 miles on it. It looks like the car was neglected. Many things don't work. But all of the major things do work. Windows, engine, top, etc... haha.
The previous owner seemed too lazy to repair the car properly. The heater is wired to a switch that's located under the dash.
Here are the problems:
-Heater is stuck on defrost
-Regardless of hot or cool setting, it blows heat. Not warm air... HEAT.
-Hi/low/off does nothing, probably because its rigged to that switch?
I am aware there is a "switch board' for the vacuum-actuated heat controls on the passenger side, but I find it hard to believe all of them stopped functioning. I wonder if it's even getting power.
I popped the hood and did a basic inspection of the vacuum lines. I believe the heater vacuum lines are on the driver side. I saw 3 diaphragms that split off from one vacuum. They all looked to be in good shape. I also replaced some dry-rotted ends from under the intake manifold. I saw a blue vacuum line, a lighter blue, a red one, and an off white. Anyone know which line goes to what?
What's the first thing I should be checking?
Thank you.
-Todd
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Joined: Sep 2013
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SL55 AMG
VIN is WDBEA66E3SC178400
Thread Starter
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Joined: Sep 2013
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SL55 AMG
Thank you for that document!
One of these would work, correct?
http://www.ebay.com/itm/Mercedes-OBD...869425&vxp=mtr
I know I can make one..I think I threw mine away when I sold my last E320.
One of these would work, correct?
http://www.ebay.com/itm/Mercedes-OBD...869425&vxp=mtr
I know I can make one..I think I threw mine away when I sold my last E320.
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SL55 AMG
They call it a pulse counter (As opposed to an OBD Scanner) because all it does it flash sequences, correct? And then you cross-reference the sequence to a number which corresponds to a problem? Just want to make sure I understand how it works.
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SL55 AMG
I got my code reader in the mail today. I'll be reading the codes shortly.
I did notice something also. When that switch is not on, the heater is off. The car also has an odd idle of 800 to 1500, erratically and inconsistently. When you flip that switch, the blower comes on, and the idle stabilizes to a healthy spec.
I did notice something also. When that switch is not on, the heater is off. The car also has an odd idle of 800 to 1500, erratically and inconsistently. When you flip that switch, the blower comes on, and the idle stabilizes to a healthy spec.
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SL55 AMG
Sorry for lack of update...
I did as you instructed. I reverted the system back to stock, and I ran the codes.
3- Lambda control inoperative
4- Air injection inoperative
3 is cruise control I believe, 4 I think is smog pump..? I don't have a California car, if that matters.
Also... I guess the previous owner was dumb. The system works ALMOST entirely correct now. Not sure why he even had a switch rigged.
Now.... I am able to use my climate control system as designed; defrost, floor, vents, even the blower settings work correctly!
BUT, it will only do heat. Hottest setting, or coldest setting, and anything in between, is just heat. Not warm air from outside.... HEAT.
I assume the heater valve is stuck open? My car does not have dual zone climate control.
I did as you instructed. I reverted the system back to stock, and I ran the codes.
3- Lambda control inoperative
4- Air injection inoperative
3 is cruise control I believe, 4 I think is smog pump..? I don't have a California car, if that matters.
Also... I guess the previous owner was dumb. The system works ALMOST entirely correct now. Not sure why he even had a switch rigged.
Now.... I am able to use my climate control system as designed; defrost, floor, vents, even the blower settings work correctly!
BUT, it will only do heat. Hottest setting, or coldest setting, and anything in between, is just heat. Not warm air from outside.... HEAT.
I assume the heater valve is stuck open? My car does not have dual zone climate control.
