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Mono Wiper Install Instructions

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  • Mono Wiper Install Instructions

    Back in 2009, I posted a complete write-up of the dreaded Mono Wiper Install. I did it in another thread discussing the subject, and thus it is very hard to search for and find. Took me awhile to find it again!

    So to make it easier to search for in the future, I am creating a thread name and this will be the first post.

    BTW…….9 years later from the actual install date, I still don't remember the name of the "ice pick" thingy. But you still need one……...
    [COLOR=#DDDDDD !important]11-29-2009, 12:46 AM[/COLOR]

    If you can, order the kit from AKG motorsport over here in the states. It's a good kit and works well.

    It is a PIA to install. Here is a complete write-up I did after doing the job. Complete step by step instructions.

    I still don't know the name of the "ice pick tool" that you need to remove the blower motor clamp, but you NEED one. It is the only tool that will unhook and hook the blower motor clamp back up. Any one else on the list that can help Luca with the name of this tool?



    I just spent a long, incredibly frustrating weekend replacing my wiper motor, which had failed during the recent 27 day non-stop rain here in Seattle. I also installed a monowiper kit since I knew I was going "in there" and only wanted to do it once. I ended up taking aprox. 12 hours to do a job that should take 4-5 at most.

    I spent 3 hours or so researching the archives looking for a good description of the job, but only found several mentions of " the worst possible job to ever do on an E30M3". No one seemed willing to relive the experience by detailing a specific procedure to follow. I used Dean Schindells DIY document to gain access, and a letter by Stephen Valeski in the archives as well as the Koala disc for the removal of the blower motor. None of these sources told me everything, but I want to thank them profusely for their help! If you haven't already you should download Deans excellent document!

    I also want to thank JR Nagy of this list and who works at Auburn Foreign Auto repair, who put up with several phone calls by me during Superbowl Sunday!

    My Chiltons was near worthless and I don't own a Bentleys. I know I should........

    I spent way too much time on deadends that I shouldn't have, such as trying to remove the assembly without taking out the blower motor housing, and trying to take out the assembly without removing the wiper motor. You can waste hours trying to puzzle your way out of this, and really need to just do the job as I have outlined it without shortcuts. Trust me, you will have enough difficulties to keep you happy even with these instructions.

    Tools: Obviously a good metric tool kit, but in particular and Important to have is a 1/4" drive and sockets. This is a small area to access.

    A combination wrench set with the ratcheting box ends is a must for the same reason as above.

    Short flat blade screwdriver. (palm size)

    A funny tool that I don't know the name of, but is an L shaped ice pick with a scewdriver type handle on it. This is to remove the blower motor clip and replace it. No other tool will suffice, and I tried several before being told to use this! Thank you JR Nagy of Auburn Foreign Auto repair for this tip!

    Lots of small wire ties.Consider a battery cable puller per Dean to remove the wiper arms, though I didn't need to use it. A small telescoping magnet to pick up dropped bolts and nuts or a "plucker". Either one will suffice.

    Good halogen or shop lights and a flashlight! Very hard to see up inside the cavity!

    Bandaids and beer! Thanks again Dean.

    1. Wipers should be parked and battery disconnected.

    2. Remove both wiper arms, then the grill under the driver side wiper. Pry carefully and it will come up.

    3. Remove the plastic cover over the wire harness at the top of the firewall. It pops off fairly easily. Then the plastic base has to come off. 3 screws, with two located on drivers side on both sides of a big wire mounting base, and one on the passengers side hiding under the wire harness. Slip the screwdriver between the wires to unscrew. Cut ALL the wire ties holding the bundle together first.. You will replace them later.

    4. Unplug the 3 plugs on the drivers side of the base at the bottom. Remove the big Y bundle in the middle from the plastic base and pivot the base/mount to lay alongside the air plenum. This gets it out of your way and allows you to push and pull the wire harness out of the way when removing components from the firewall cavity.

    5. Now you can get to the metal cover on the firewall. Four 7mm screws hold this on. Most obvious is drivers side top, just inboard the fuse box. Next is about 6" below and inboard, behind one of the 3 wire harness plugs you unplugged. Now go to the passenger side of the plate and look for one behind the wire harness close to the screw that you have already removed. Then the 4th one is below and slightly inboard easily visible. Very hard to get to though. Pull the plate up and off.

    6. Now you are looking at the blower motor cover. Two nylon straps hold the cover on. Clip the thin plastic that connects the top and bottom straps and then unfasten the top and bottom straps. Koala has a good picture and description. Rotate them sideways out of the way as best you can. Pull the cover out and down to clear the cavity and then up and out of the way. Remember which is the top and bottom for re-installation.

    7. To remove the blower motor use the "special tool", that 90 degree icepick. Stick the end in the little hole at the bottom of the metal clamp and pry it off it's catch point. You can figure out how to use the thing, I can't describe it exactly. To remove the motor, rotate it to get at the wires and pull the wires off. Move them down and out of the way. Don't let them get caught in the fan blades and break a blade. Use your fingers to pull the motor and fans out. This is most tricky as you need to really push the wire harness out of the way, and be careful pulling the fans through the opening. They will "give" a little but are somewhat brittle and you don't want to break them. However, I had that sucker in and out more times than I care to admit trying to get it back in, and it is do-able. Don't remove the fans from the motor as it is a balanced unit.

    8. Now life gets interesting............... The top of the motor housing has to come out. Yes it does! You won't want to take it out, but it has to go...........Look for two small clips on each outboard front and pop them off with a screwdriver. Now have fun getting your hands into the back of the housing and "feel" for the two on the back, almost directly in line with the front ones. This is where small hands and the little flat bladed screwdriver come in handy. Pop the two clips in back off. If you've gotten this far you already are guessing that they are going to be godawfull to put back on. Next, you have to remove the side flaps. The only way is to carefully pry the flaps out of the box frame by the front and rear pivot points and let them slide in towards the middle, still connected to the bottom of the assembly. (These are even worse to put back in...............) Lift the top of the motor housing and pull out of the cavity. Congratulations! Take a break

    9. Ok, lets get that wiper motor and linkage out of there! Take your combination ratchets or small quarter inch drive and remove the three motor bolts and drive nut. Once started, they are usually removable with your fingers. Very difficult to get to but can be done. Remove the nuts from the external wiper shafts and the nut holding the assembly inside the cavity. You will plainly see it. When the shafts drop down somewhat you can get the cover off the motor and remove the motor after unplugging it from it's harness. Once the motor is removed, the linkage can be pivoted up and towards you with the shafts dropping down inside the cavity. You may have to move the arms/linkage to gain better clearance. Carefully maneuver the passenger side out followed by the drivers side. Be careful not to dent the sheet metal under the windshield. I tried doing this without removing the motor first but didn't have enough room to pivot the assembly. Fairly easily done if motor is out!

    10. I installed a monowiper kit from AKG motorsports. Excellent kit, good instructions for parking the wiper either straight up DTM style or in the normal down position. I elected to park the wiper in the up/DTM style. Got it first time following the instructions. Be sure to check everything before putting the blower motor housing back in! You don't want to have to take this all apart again!

    11. Reverse order. Place the linkage assembly in loose. Slide motor in. Bolt up wiper shafts to body and then bolt up motor and drive linkage. One of the motor bolts is exceptionally hard to get in and out but it can be done! Put cover on motor.......This may mean unbolting shafts to make room to get it over motor, then bolt up shafts, bolt assembly inside cavity and be sure motor is plugged in. Power up and check operation! Make sure the wiper is installed to check parking.

    12. Good luck getting the blower assembly back on. The flaps are a pain in the ass to get back in their hinge points. I have no hints here, all I can say is eventually I got them back in place. I used a large socket in my hand to get in behind the back clips and press them over their catches. I pressed the socket against the clips to flatten them to get them to clip. I never felt or heard them clip, but gingerly pulled on the housing and it seemed to be fastened. I used a large flat bladed screwdriver to clip the front ones. By this time the metal strap that holds the blower motor may have come loose. It needs to be hooked in the back of the housing. I made a serious mistake here, thinking that it clipped on the metal band you see directly in the back of the housing, because it had come loose without my seeing where it latched on to. It actually clips directly to a point in the plastic about a half inch up from the metal band. If you clip it to the metal it won't be long enough to secure on the front side with the motor in. IT CAN INADVERTANTLY SLIDE DOWN TO, AND BECOME CLIPPED ONTO THE METAL BAND WHEN YOU ARE TRYING TO GET THE MOTOR BACK IN. This happened to me twice, causing much cussing, swearing and general discomfort for my 3 year old within earshot. When this happens, it is too short to latch on the front and you have to take the motor out again and re-attach the metal strap in the proper place in back. The front is easily latched with the "ice pick" tool. Don't forget to plug the wires back in and rotate the motor to the rear before latching the band. If your blower motor has been squeaking, this is a good time to lube the motor shafts.........

    13. Place the blower motor cover back on the housing, secure the nylon straps. Rebolt the firewall cover in place, screw the plastic harness mount in place, plugging the 3 plugs back together and using the plastic wire ties to replace the ones you cut. Snap the cover over the wire harness, replace the wiper grill and wiper arms if you haven't already. If you installed a monowiper, AKG has a small black plug you can use if you want to plug the hole in the grill.

    Congratulate yourself, drink profusely and take some ibuprofen to ease the aches and pains you will develop from all the contortions and laying across your motor working inside the firewall cavity. I hope this write-up helps any future adventurers willing to delve deeply into this nether region on our M3's.


    William Buchanan
    '91 M3
    Bastos/Castrol DTM Tribute
    259000 miles and still an immense pleasure to drive.
    "The original M3 is utterly brilliant in ways the people at M have either forgotten about, or choose to ignore"

  • #2
    Yes it was a very painful ordeal, I'm very glad I did it a very long time ago!! I don't think I could make myself do it again


    • #3

      I agree completely!

      A couple years after this install, I had to go back in and replace my blower. I hope I never have to go back into that accursed space again.
      William Buchanan
      '91 M3
      Bastos/Castrol DTM Tribute
      259000 miles and still an immense pleasure to drive.
      "The original M3 is utterly brilliant in ways the people at M have either forgotten about, or choose to ignore"