I have replaced the blower motor on a 1990 300e. It is not difficult. The Mercedes mechanic wanted to charge me $1,000.17 to replace the blower motor. After having done it once, ( I put the motor in backwards!) I redid it and it took seventeen minutes to expose the blower motor. I now no longer use this mechanic. You access the blower motor by taking the windshield wiper motor off completely. Remember where every bolt goes. Take the windshield wiper armature off intact. It helps to always place the parts on the same side of the car when you take them off and in the same orientation. There are silver clips that hold the blower motor housing on that need to be pushed off and they must go back on or the fan will always have a rattle/buzz. Ask me how I know that). Before buttoning it up, it is a good idea to turn the A/C on and test the fan. Make sure the squirrel cages are spinning in the correct direction. I tested mine before closing things up and attributed the lesser air-flow to the fact that I had not yet put the top of the blower fan housing on. I was wrong. The silver clips I spoke about earlier are located all along the front and sides as well as two hidden ones on the back that you really will not know about unless you have done this before. Also, put a towel in the bottom of the plastic deck just below the windshield wiper. You will lose a screw or two down that bottomless air ducting if you do not. (Ask me how I know that as well) also, I used only hand tools. Nothing electric or air powered. A real mechanic with those tools could most likely replace that motor in thirty minutes or even less. And careful with the windshield wiper blade armature. I think it would be fairly easy to crack a windshield. Hope this helps and good luck.
Friday, December 8th, 2017 AT 5:02 PM