Slow Windows.... Any Advice? BTW, I got bit by a shark...

[scottevest]

Although when I first purchased and received my e9, the windows worked "well", meaning they went up at a fairly slow speed but consistent speed all the way to the top. Most of the windows went up at about the same speed. Now, however, all 4 windows go up at very different speeds, and some seem to almost stop entirely for a brief period while making their way to the top. And, both front windows take full minutes to get up the last inch or so. I thought someone previously suggested that I could replace the motors with a more recent version, but I am not sure if I was just dreaming when I read that.

Someone in the Parts section contacted me and offered to sell me the 2 motors for front windows for $125 for the pair. Seems fair, but if they are as slow as the ones I have now, not sure worth doing anything. Any ideas are welcome.

I hope everyone is having a great Sunday! I just finished skiing and now hanging out to watch football with the wife and poodles, including our newest edition, Susie Q, 9 weeks old and adorable.

On a side note, I just learned that I will be appearing on ABC's Shark Tank later next year. I filmed my episode in September but didn't know if it was selected until just Friday. I am so excited. Stay tuned! I will let you know air date if interested.

Thanks for all the great advice and virtual friendship.

Scott

 

[rb1971]

Getting the windows right has been the single most frustrating part of my entire restoration project (and I did a lot of fairly individualized stuff!).

There could be several issues, and the motors are only one of them. I had all of the following:

1. Bad motors (1/4 not working at all, 1/4 close to dead).
2. Regulators bent or otherwise incorrect (both of my front windows were replaced).
3. Tracks warped (looks like someone at one point hit the bottom (??) of the passenger door with a hammer near where the rear track connects, had to cut off about 1/16" to make it right).
4. Door fitment not quite correct (recently replaced my passenger hinges).
5. Switches (I replaced all 6).

The frustrating thing for me is not all the work required, which is as a general matter expected when problem-solving on a 40-year-old handmade car, but the fact that even if everything works perfectly, you've still got a pretty poor system.

There are two things that concern me in your post. First, that the window speeds have changed indicate that something has happened. Could be the motors, but could be a number of other things.

Second, the fact that the windows are extra slow near the top would both me a lot. That indicates there is some kind of bind on the system. I would suspect some sort of window-body or window-seal interaction, or stress on the mechanicals. Unless it were raining, I probably wouldn't hold down the switch when the window was running very slowly since that could cause damage to the internal parts.

 

[Nicad]

Congratulations on being in a shark tank Scott.

 

[HB Chris]

Your 74 has better motors than the earlier sardine can motors which changed in mid 73. You can use e28 rear door motors as a direct bolt in but I don't know if they're any stronger, they look the same. Going price was around $40 each but demand may have raised price.

Best thing to do is clean the tracks, they get incredibly gummed up with old grease. Be sure all wire connectors are clean as well as any grounds. The cable from door to A pillar gets pinched causing intermittent failures, there is a connector behind the kick panels too. The regulator as mentioned could be bent but if all worked and now they are slow I would attack the tracks first.

Chris

 

[Tony_V]

Try to connect the motor directly to a battery and check if they still are slow.
For me the biggest problem was the ground.

 

[pmansson]

One or two ideas

First of all I don´t agree on the early vs late motors. In 1973 BMW changed the inner door panel (metal part) to suit the new regulators and new motors. I don´t know why, but I do know that the early ones are much easier to remove and mount back in place, AND that the early setup allows a much faster movement of the glass, provided all is clean, lubricated, adjusted and well wired. This is a fact.

Secondly, your glass running very slow for the last part going up could be due to your new U-shaped felt liners, if you changed them. It took me lots and lots of time and trial & error to discover this. What is currently on sale at all the usual suspects comes from the one and only manufacturer in Germany. They are about 10% too large in all dimensions. This makes the glass fit too tight. At the bottom there is just a small section of the glass that runs in the felt and hence it´s negligible. Half way up it begins to slow down, and for the upper 1/3 it needs assistance by a hand, esp the last 20%.

Lastly, the rear, slanting runner needs to be carefully adjusted. Not to be too loose against the moving glass´ insert, and not too tight, strangling the movement. Also clean the 4 ball bearings witht their metal wheels, and be careful not to loose the spring which is usually hidden in old stale grease...

With all my E9s, I have done a lot of work in the doors, and am now quite confident on the issues, but I wish that the German manufacturer had gotten it right when he set up his tooling for making the U-shaped felt liner...He just wasn´t careful enough.

 

[Stan]

Try to find a post from Kurt D
He wrote out detailed instructions for window motor upgrade.

 

[HB Chris]

Stan,

Kurt's write-up focuses on the early motors.

Chris

 

[Stan]

replace E9 window motor with E28 window motor

http://sites.google.com/site/kdelimon/windowmotorconversion1

this should go in our TechInfo section

 

[jmackro]

As others have written, is is essential to adjust the tracks so that the windows have a minimum of friction.

Two other tricks:

- I installed two relays next to each motor, and ran a 10 gauge wire directly from the battery to power the relays. Now the switches on the console only handle the few milliamps required to actuate the relays. This made a huge improvement; the original switches and wiring have quite a bit of resistance, resulting in less voltage to the motors.

- I also ran a dedicated ground from the motor, through the door gap, to the chassis. In other words, I didn't rely on the door hinges as a ground path.

Of course, I didn't test these two measures separately - my guess is that the direct power feed + relays make the greatest difference.

 

[matthewp]

i just replaced the motor on the right rear on the weekend, made the world of difference.

 

[Stevehose]

As I was putting my car cover on last night I was wondering what my next project is going to be - I remember jjacobs also mentioning this upgrade - I will be sourcing 8 relays and embarking on this task.

As others have written, is is essential to adjust the tracks so that the windows have a minimum of friction.

Two other tricks:

- I installed two relays next to each motor, and ran a 10 gauge wire directly from the battery to power the relays. Now the switches on the console only handle the few milliamps required to actuate the relays. This made a huge improvement; the original switches and wiring have quite a bit of resistance, resulting in less voltage to the motors.

- I also ran a dedicated ground from the motor, through the door gap, to the chassis. In other words, I didn't rely on the door hinges as a ground path.

Of course, I didn't test these two measures separately - my guess is that the direct power feed + relays make the greatest difference.

 

[bobabob]

Your 74 has better motors than the earlier sardine can motors which changed in mid 73. You can use e28 rear door motors as a direct bolt in but I don't know if they're any stronger, they look the same. Going price was around $40 each but demand may have raised price.

Best thing to do is clean the tracks, they get incredibly gummed up with old grease. Be sure all wire connectors are clean as well as any grounds. The cable from door to A pillar gets pinched causing intermittent failures, there is a connector behind the kick panels too. The regulator as mentioned could be bent but if all worked and now they are slow I would attack the tracks first.

Chris

My '74 3.0CS LF window goes down fine until the last third, then shudders, then either stops or slowly continues all the way down. Mechanic says new regulator. Thoughts?
Thanks!

 

[jmackro]

My '74 3.0CS LF window goes down fine until the last third, then shudders, then either stops or slowly continues all the way down. Mechanic says new regulator. Thoughts?

Well, one thought is: "do you really want to spend the $$ for a new regulator?" Maximillian has them, but they lefts are $422 (the rights are priced lower, "only" $361).

Another thought: "how does the mechanic know it's the regulator, instead of the window binding on the tracks? If the windows move OK through the first 2/3 of their travel, and only bind up on the last 1/3, I would suspect track alignment, rather than a problem with the motor or regulator.

But honestly, until you have it apart, it's all conjecture.

 

[bobabob]

Thanks, Jay--that was my thought also, but checking/aligning the tracks appears to be a big challenge. Of course, used!

 

[Stevehose]

Pull the door panel off, disconnect the rod to the glass, and slide it up and down manually, you'll be able to determine where/how the binding occurs.

 

[bobabob]

Beautiful. Thank you.

 

[Mark Jarman]

Adding a note to this thread in case it helps the next person troubleshooting power windows.

I had removed, cleaned up and reconditioned my rear windows following this great thread

I bench tested my motors and window mechanism and it was working great before re-installing the rear window unit in the car.

Once in the car, I hooked up my old window switch to test the window and it wasn't working well. I had to use my hands to assist the motor just like it was before I cleaned up and greased everything. Further, I could feel the switch getting warm which kind of freaked me out.

I read a bunch of threads about installing relay switches and was thinking that's what I'd need to do to have well-functioning windows, but somewhere I read a forum member making a comment that relay switches and new E28 motors wasn't necessary. You just needed to make sure all components of the original equipment were in good order and the switches didn't have carbon buildup. Luckily, I had a few new switches to test. I tested with a new switch and my window worked perfectly as it did in the bench test. Fast and reliable. My E9 is a pre '74 so the switches and motors are that version. Switches are still available at W&N for around $43.

While the window motor upgrade and installation of relay switches might be a better design and a good upgrade for some people, I don't think it is absolutely necessary to get your windows working well.

MWJ

 

[Arde]

I agree with that advice, though once the new switches are in, one should resist the temptation to keep pushing on the switch when the window has stopped, else it will overheat and carbonize again.

 

[jefflit]

Listen to everyone. They aren't wrong in that it can all work as built by the factory if everything is in good working order.

That said, i dont run motor current through switches on any car i own. I always install relays. And i replaced my mototrs with e28 versions because they are faster,. If you are still interested in e28 motors you can see the speed difference in this thread. https://e9coupe.com/forum/threads/electric-window-motor-upgrade.414/page-3#post-172071