Cooling fan not operating, I HAVE SEARCHED!!! A LOT! haha
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2003 CL55 AMG
Cooling fan not operating, I HAVE SEARCHED!!! A LOT! haha
Hi everyone, I edited this so look below this paragraph for fan information. I have a 2003 CL55 AMG and can not get the fan on to save my life! I assumed it was just a bad fan and module so put out $500 for a new one and after installing I still have NOTHING! I have searched the forums only to find dead ends. Before replacing the fan I found that the 20A fuse was missing for it so I put in a new one and would get a VERY VERY short "Coolant Visit Workshop" every so often off and on and no fan. After removing the fan I got it all the time. With the new fan in place I haven't had it come on yet and the fan STILL isn't kicking on. I have read of hidden fuses in the range of 125-150AMP but I would imagine that more things in the car wouldn't work if one of them blew. Any help would be greatly appreciated.
What I have discovered in my voyage to resolve this issue.
Fuse 87 - 20AMP - Located on passenger side under the smaller box is associated to the fan
Fuse 30 - 20AMP - Located on passenger side in the primary fuse box is also associated to the fan
Fuse X4 - 100AMP - Located in the trunk behind the lining above the battery is ONLY for the cooling fan and if it pops the WHOLE box needs to be replaced
Fan should run when MAX AC is on - mine does not
Fan should turn on once 90C is reached - mine does not
Supplied 12v to fan speed wire and fan fires right up BUT I have a Coolant Visit Workshop!
Computer is requesting 40% power from the fan but the signal isn't getting to it.
Need to know where the yellow/blue stripe wire goes to so I can investigate further.
What I have discovered in my voyage to resolve this issue.
Fuse 87 - 20AMP - Located on passenger side under the smaller box is associated to the fan
Fuse 30 - 20AMP - Located on passenger side in the primary fuse box is also associated to the fan
Fuse X4 - 100AMP - Located in the trunk behind the lining above the battery is ONLY for the cooling fan and if it pops the WHOLE box needs to be replaced
Fan should run when MAX AC is on - mine does not
Fan should turn on once 90C is reached - mine does not
Supplied 12v to fan speed wire and fan fires right up BUT I have a Coolant Visit Workshop!
Computer is requesting 40% power from the fan but the signal isn't getting to it.
Need to know where the yellow/blue stripe wire goes to so I can investigate further.
Last edited by CL55_AMG_GUY; Sep 9, 2014 at 04:26 AM.
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2003 CL55 AMG
I checked to see if I was getting power at the plug and the results of the 4 post plug were as follows:
2 large wires, 12V and ground
2 small wires, 12V and 0.35v noting that the .35 is probably the signal wire and the 12v is power for the control module.
If anyone has any recommendations for me that would be great because I am out of ideas
2 large wires, 12V and ground
2 small wires, 12V and 0.35v noting that the .35 is probably the signal wire and the 12v is power for the control module.
If anyone has any recommendations for me that would be great because I am out of ideas
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2003 CL55 AMG
Checked the hidden fuses under the passenger side foot well and everything was fine there. Did some more searching and discovered that the fans primary power wire has a 100AMP fuse in the trunk by the battery, checked it and all is in order... Maybe the replacement fan I received is defective but I find it strange that after installing it I no longer get ANY faults even if the car gets to 100C and higher with AC on MAX while it is 100 degrees here in Texas! Fan just doesn't want to turn on... I cross referenced the part number I received with Behr's site and it is the correct unit for the car... I hate to take it to someone but I just might have to.
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2003 W211 E55, 2003 W220 S600
is the coolant level fine in the car? I know it is unrelated but on a 360 modena if the coolant level is low the radiator fans will not turn on.
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2003 CL55 AMG
Disconnected temp sensor, car strongly disliked it by running horrible. I read on another forum that the 4 prong fan (integrated control module) would go in to TURBO failsafe if it didn't detect a signal from the ECU so I unplugged the fan, removed the yellow with blue stripe wire as it tested at only 0.35v showing to be the signal and BOOM fan fired right up! So does that mean that the SAM module is bad? Wouldn't I have some sort of check engine light or warning signal? I feel like I am getting close to a solution. Some people in the CLK board said that often times neither the fan or the ECU was bad and in fact was the harness between? Any other suggestions would be GREAT!
Thinking maybe jumper to replace the wire BUT it is strange that it shows voltage so it leads me to believe that it is the ECU that it plugs into.
Thinking maybe jumper to replace the wire BUT it is strange that it shows voltage so it leads me to believe that it is the ECU that it plugs into.
Last edited by CL55_AMG_GUY; Aug 20, 2014 at 03:21 AM.
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2003 CL55 AMG
Ok, I bought the Launch EasyDiag tool ($37 shipped) and the Mercedes software ($40) so great buy! With the software I was able to find that the computer is requesting 40% power to the cooling fan which tells me the ECU is operating properly. Can anyone supply me with a wiring diagram from the M4/7 connector specifically for a 2003 CL55? I just need to know where the yellow/blue stripe wire goes to? This wire controls fan speed and is currently only putting out 0.35v so somewhere between the ECU and this wire it is losing the signal but I can't trace the wire without unwrapping everything which is something I don't want to do... Thank you in advance!
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CL55
10 years on, I'm guessing no solution was found? I have this problem and it seems fairly common, but on no forum or YouTube (looking at other models with the same fan setup too) can I find any solution. My fault code reader can activate the fan at any speed, but with the engine on, nothing.
The choice seems to be an ECU fault, or my cheapo after market fan / controller (replaced by teh previous owner) not responding when the engine is running - perhaps due to a voltage drop compared to forcing it to work with just the ignition on?
The choice seems to be an ECU fault, or my cheapo after market fan / controller (replaced by teh previous owner) not responding when the engine is running - perhaps due to a voltage drop compared to forcing it to work with just the ignition on?
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CL600 W215
I have the same problem and also not been able to find the answer anywere.
In my case I do have corrosion at the ECU and had to create a jump wire to bypass a damaged pin, so yes I could have something in there going on potentially.
I also had major corrosion in the SAM on that right side so I have replaced it. That resolved my headlights and some other gremlins but still no FAN.
I am going to order a new fan to rule that out.
I also have an issue with my horn not working, which is odd because I hear the relay activate and I know the actual horn works.... that may be unrelated wiring issues.
In my case I do have corrosion at the ECU and had to create a jump wire to bypass a damaged pin, so yes I could have something in there going on potentially.
I also had major corrosion in the SAM on that right side so I have replaced it. That resolved my headlights and some other gremlins but still no FAN.
I am going to order a new fan to rule that out.
I also have an issue with my horn not working, which is odd because I hear the relay activate and I know the actual horn works.... that may be unrelated wiring issues.
TOP causes after checking the fuses and perfuse box
.
Cause 1
Front sam dead. do not repair, you can replace it with a used one from ebay
needs to be coded, even if it's the same car, it's options dependent
Cause 2
Fan module dead
replace the Fan
.
Cause 1
Front sam dead. do not repair, you can replace it with a used one from ebay
needs to be coded, even if it's the same car, it's options dependent
Cause 2
Fan module dead
replace the Fan
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Joined: Jul 2022
Posts: 12
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CL600 W215
Thanks BenzNinja.
Turns out I had both issues. My SAM was buggered with corrosion. I ordered a bunch of used ones on eBay and kept the one that operated all my accessories. no one I could find could code a used module and I didn't fancy buying a new one!
After that I ordered a fan and boom, all working well now.
For me the main sticky point was not being able to test the fan and module outside of the car ... is there a way to do that do you know?
Thanks BenzNinja.
Turns out I had both issues. My SAM was buggered with corrosion. I ordered a bunch of used ones on eBay and kept the one that operated all my accessories. no one I could find could code a used module and I didn't fancy buying a new one!
After that I ordered a fan and boom, all working well now.
For me the main sticky point was not being able to test the fan and module outside of the car ... is there a way to do that do you know?
Turns out I had both issues. My SAM was buggered with corrosion. I ordered a bunch of used ones on eBay and kept the one that operated all my accessories. no one I could find could code a used module and I didn't fancy buying a new one!
After that I ordered a fan and boom, all working well now.
For me the main sticky point was not being able to test the fan and module outside of the car ... is there a way to do that do you know?
