W220 Radiatior fan won't run
Thread Starter
Newbie
Joined: Jan 2023
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W220 S500 99'
W220 Radiatior fan won't run
Hi everyone,
this is my first time here so greetings from Poland.
I have a problem with a W220 s500, year 1999.
After my accessory belt broke and I replaced it, temperature problems began, I noticed that the fan was not working.I took the fan out and something was blocking it - probably pieces of a broken belt.
Unfortunately, it was impossible to disassemble it to replace the bearings, so I bought a used one with the engine (working).Unfortunately, the fan was still not moving.
I checked the fuses and they were ok. I was looking for relays and I found the fan relay located under the right lamp, after disassembling the housing it looked burnt - the paths stratified.I bought a working module used and the fan still did not move.
The last thing that came to my mind was the pre-fuse.I checked them and replaced them with new ones, the fan still doesn't work.I checked the engine temperature on the air conditioning panel in the hidden menu on channel 6. This is the sensor, right?
What else can I check?did i miss something?
this is my first time here so greetings from Poland.
I have a problem with a W220 s500, year 1999.
After my accessory belt broke and I replaced it, temperature problems began, I noticed that the fan was not working.I took the fan out and something was blocking it - probably pieces of a broken belt.
Unfortunately, it was impossible to disassemble it to replace the bearings, so I bought a used one with the engine (working).Unfortunately, the fan was still not moving.
I checked the fuses and they were ok. I was looking for relays and I found the fan relay located under the right lamp, after disassembling the housing it looked burnt - the paths stratified.I bought a working module used and the fan still did not move.
The last thing that came to my mind was the pre-fuse.I checked them and replaced them with new ones, the fan still doesn't work.I checked the engine temperature on the air conditioning panel in the hidden menu on channel 6. This is the sensor, right?
What else can I check?did i miss something?
Super Member
Joined: Dec 2007
Posts: 980
Likes: 224
2005 S500 Designo
You've done your legwork, and unfortunately there's nothing I can offer beyond speculation. Maybe someone else here can chime in with a quirk of these cars. Have you considered testing the fans with 12V? I assume the fans spin freely? It'll take a lot of amps to run, but whatever power supply you have should be able to get it spinning. Otherwise have you checked with a multimeter?
If you have a mercedes computer, I believe you can manually engage the fan.
If you have a mercedes computer, I believe you can manually engage the fan.
Thread Starter
Newbie
Joined: Jan 2023
Posts: 3
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W220 S500 99'
Thanks for the answer.
Yes, I tested the new-used fan under the power supply before I put it in the car and it worked properly.
have a multimeter but I'm out of ideas where to look. Now all I can do is check the wires and will have to remove the fuse box on the left side (facing the car). The wire from the fan relay goes towards the fuse box.
The fan did not want to move connected to the computer.
hen the air conditioning is turned on, the fan should start immediately regardless of the engine temperature (I think) because the COOLANT - WISIT WORKSHOP error immediately pops up.
Yes, I tested the new-used fan under the power supply before I put it in the car and it worked properly.
have a multimeter but I'm out of ideas where to look. Now all I can do is check the wires and will have to remove the fuse box on the left side (facing the car). The wire from the fan relay goes towards the fuse box.
The fan did not want to move connected to the computer.
hen the air conditioning is turned on, the fan should start immediately regardless of the engine temperature (I think) because the COOLANT - WISIT WORKSHOP error immediately pops up.
Thread Starter
Newbie
Joined: Jan 2023
Posts: 3
Likes: 1
W220 S500 99'
Unfortunately, the local mechanics only have Delphi or Texa interfaces. I need to find someone with star diagnosis and they are not helpful. It's really annoying that this interface is so expensive for a 24 year old car 
Super Member
Joined: Dec 2007
Posts: 980
Likes: 224
2005 S500 Designo
That said, there are some.. dubious options available if you check the internet, ebay, or even this forum to get a working DAS or Xentry or whatever.
