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DIY: W210 computer box cooling blower motor replace.
It's getting hot and hot, you can check your computer box under the hood, is there wind blow from the bottom.
if not, the blower's motor maybe dead.
You can check follow link for the video wind blows:
follow the steps to replace it.
▼computer box under the hood, you need to remove 4 screws to open the cover.
▼you can see the fuse box here in blue square, remove every socket and wires, do not pull it out hardly, please be gentle and check is there any plug on it.
if you can't remove the wire, take a break and close look.
▼Look at me, I broke this socket, fortunately it can still put it back.
▼then you can remove the transmission computer.
▼remove the socket plug from the ABS computer, you can slide the red part toward the arrow, the the socket will jump up.
if not, you need to strength your finger power.
▼remove every wires and computers, you can see 5 8mm bolts in red circle.remove it. then you can move out the upper box.
▼lose 4 10mm bolts in the red circle here, it's a little bit tricky, you need a angle socket to do it. Do not remove the whole screw, pay attention don't let it fall out.
▼You need this...
▼Now you can remove the whole computer box, and here is the small blower. when you remove the box, be careful those color
pipe, don't pull and break it.
▼2 screws to move the blower.
▼Take apart this small blower, pretty easy, no screws.
▼Use the screw driver, reach in the gap between the fan and the housing, then turn the screw driver.
fan will move from the motor axle.
▼Be ware of the gap, don't let the fan touch the housing when you put the fan into the new motor.
You'd better turn it and check if it turn smoothly or not.
Ok, now put the blower back into your car.
But I found out the new motor is spin too fast, it became pretty noisy while I turn the key on.
So I put a small device to lower the voltage, for let the motor spin slowly.
▼This DC-DC lower voltage module, pretty cheap, cost me USD2 here in Taiwan.
▼Put the wire on it first. and before you attach to your car, you'd better check the output voltage by meter first.
I lower down the voltage from 12V to 6V. by turn the small gold screw counterclockwise.
▼I use the "melting glue" to protect the welding spot and attached on my car, working fine, cooling the computers and not so noisy.
Last edited by Richard Hsu; May 11, 2018 at 03:50 AM.
I eventually found a suitable motor and installed it. It worked for quite a number of years. Then one day while driving, the engine on our W210 cut out and would not re-start. Had to get it towed home. After a several weeks of testing and diagnosis, I eventually found that the blower motor had shorted. For unknown reasons, MB chose to use the same source of 12V power for the blower motor as the main ECU! One I disconnected the blower from the K40, the engine started.
In the UK and maybe europe, W210s don't have that blower. I installed a temperature sensor and found that the apparatus case did not get unduly hot. The way the blower works, is that it sucks air conditioned air from the interior of the car and blows that cool air into the apparatus case. Well, our A/C no longer worked, so that wasn't going to help much anyway
Doing this again was a deterrent!
Last edited by 107123210; Dec 26, 2025 at 08:16 PM.
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