Glove box removal and Fan Blower Motor oiling

[WindTrackMind]

My 2008 has 48K miles on it. The Fan blower for the AC started acting up (intermittent) and finally this last week stopped working.
Of course I was on a 8 hour trip and needed AC so I learned that the fan motor bearings could be unsiezed by jumping the 25A 12VDC center console straight +12VDC to the fan motor itself. Run it for 20 seconds and it warms up enough for the fan control to run it normally until the next day.. even a 'decently sized' 12VDC pigtail will heat up due to the 20Amps that I estimate flows, so only use a pigtail for 30 seconds or risk meltdown. I used female bullet connectors at the end of the 12VDC pigtail to jump it into running, and removed it once it ran for a 20-30 seconds.
I found previous posts that mentioned warming up grease during application with a heat gun, and so I thought I would try that. I could not find info on how to remove the glove box, so I'll post what I learned, and also what I did to the fan blower motor for now. (motor was practically siezed up, now it spins a fair bit better but still no free spinning) Motor does now work without jumping it externally. (for how long I do not know.)
I think the motor has high amount of brush residue, and that might be gumming up the rotor.

Here's how I suggest Removing the Glove Box: remove 4 screws location in green, one is on bottom of right side panel, then pull that right side panel straight off and away.
The three green screw locations at bottom of glovebox are inside the glove box of course, yes you must empty the glove box. Once those are away, the glove box drawer comes away. If this hinge ever fails, I plan to use nylon cloth webbing or maybe milk jug material as a replacement hing.
Remove the top 3 screw locations marked with orange next, then pull the glove box housing away from dash, removing the wire to the lamp and ventilation hose as you go.
Reinstall is simply the reverse.

 

[WindTrackMind]

To remove the Blower Fan motor, you might have to remove one screw at right that will allow the structure to give more clearance when you remove the motor.
Simply unhook the power to the blower motor, and twist the motor end CCW to remove. There is a plastic spring loaded friction at about 5AM on the dial, you can ignore it or pry it up a 1/8" to see if it allows it to twist easier.
Here's a pic of the motor and orange pointer to the spring keeper that I didn't have to pry to twist. And next to that, a pic of the dash with motor removed.

 

[WindTrackMind]

As for greasing/oiling the shaft of the motor, you have to first pull the plastic motor housing off. Simply push the rubber wedges into the housing, and the motor starts sliding out. The electrical connector has a center tab that you must also push to one side, and it will also leave the housing.
You can see rubber wedges marked in green, and also the electrical connector tab in green.
I marked the shaft end in orange, where I applied grease, and melted that grease into the bearing with some mild heat gun application.

 

[WindTrackMind]

This is the other end of the motor, this end faces forward. I show one of the two long stator brushes marked in green (brushes still have lots of life it looked like), no serious wear to stator plates that I saw.
I marked in orange circle where I applied oil to this front bearing. I could not apply heat due to plastic fan blades. And I had to drop the oil down onto this bearing, so that it might enter between shaft and bearing. I pointed fan down, and applied oil in downward angle.
Application and spinning, application and spinning.. lots of hand spinning.. it is now probably 5 times more free. And it works without any other tricks at this time.
There was a whole lot of black build up in the motor, it would fall out when knocked, I believe this to be brush debris, and probably adds to the siezing up. I removed what I could of that black residue also.
You can actually see that 1/2 of the fan has a black coating of residue, that's how it looks without touch up.
Put it all back together, and it should live a while longer I hope.

 

[WindTrackMind]

Update: about 2 weeks later it's still working. It made some squeaking again a few days after the above oiling/greasing, but has been largely silent since. I do run it on high when I remember to, for at least a couple of minutes. I suspect that running it only on a low setting might ask for trouble later, so I try to run it on high, since I did not often run it on high. If you do the above maintenance, I suggest you run it on high at first to break it in again.
I believe this is a motor/bearing combination that requires preventive maintenance to the bearings.

 

[Vanman2004b]

This sure saved me some time, aggravation, and money.

 

[Dougflas]

One trick I use on some models of blower motors is to drill a small hole in the end caps and squirt oil into the holes. I see that this would not work on this particular motor but there are others out there that will work this way. It sure is easier to remove the motor on TIN's!

 

[WindTrackMind]

Update roughly a year later, motor makes a touch of noise and hesitation (sometimes) upon start up, time for a new oiling.

 

[fishermunn]

special thanks from me!
my wife and i are on a two week trip to florida and texas. my fan started to squeak then quit. the thought of traveling with out air conditioning sent me looking for immediate help.
i am so fortunate to find your post about how you got your fan running. your pictures and description of how to get the motor unstuck saved me. i was able to do the job in the motel parking lot, under a shade tree in under two hours.
i had limited resources, but was able to use some wire connected to the positive lead under the hood and a wire to the ground on the frame to fire up the blower motor. it was a little sketchy but the motor squealed and finally broke loose. after using some motor oil on the bearing it started to run smoothly.
to repeat myself, thank you for sharing. it saved me many hours of running down the highway with the windows down, listening to roaring of the highway noise trying to drown out the noise from the passenger seat.
best,
lance

 

[heavy351]

2008 3500 144

This thread saved me from freezing to death... Blower motor quit after sitting in the cold last weekend. Drove all yesterday with heat only above 40MPH. I actually went the long way so I could stay warm. Anyway, reaching through the air cleaner box with a long screwdriver I gave the blower a little turn and could see it wanted to spin but just couldn't get going. Also, it had been making intermittent squeaking noises. Bearing issue made perfect sense. Pulled it out using the instructions above with the only variation is that I removed a screw in the bottom right of the dash frame to give just a little more clearance to work it out.

Pulled from plastic housing and all looked good no burn marks. The fan was fairly stiff to turn and you could feel a slight lumpy notch in some positions. Chucked up the end of the shaft on the squirrel cage side in my cordless drill and there was that squeak I had been hearing. Turned the fan so the rear of the shaft was facing up and added Motorkote with a coffee straw to the gap between bearing and shaft. Ran drill about a min until squeak was gone. Turned on side 45 degrees and applied some more to the shaft just above the other bearing and let it run downward while spinning with drill. Fan now turns smoothly with considerably less effort but will not spin "free" not sure if it is supposed to..

Installed and works perfectly!

THANKYOU SPRINTER-FORUM

 

[PaulDavis]

The blower motor on my 2010 NCV3 seized up a few weeks ago. Followed the simple steps above (just used a regular motor oil because I couldn't find my heat gun), and everything is working again. Fantastically useful thread! I can't imagine what the dealer would have charged me to fix this. Total time (including driving to Lowes to get some oil): less than 1 hour.

 

[blisspacket]

Thanks Windtrackmind. I pulled the cabin filter off under the hood and checked the blower action with a dowel. Yes, it's ready for a lubing. Too bad the Benz boys shortchanged us on this one. 2008 with 31k miles.

 

[blisspacket]

Did the oiling. I found no appreciable difference after oiling. There's a thrust washer on the shaft that created a drag that I mistook for lack of oil with my dowel test. Nice construction down there. Apologies to the Benz clan!

 

[Burkilimo]

Same thing happened to one of our sprinters. Started with a low pitch intermittent squeak and then motor stopped working. Would work when a power probe was applied to it. Before swapping it out for a new motor - I decided to liberally drench it in wd-40 and then let it sit for a few before using the shop compressor blow gun to blow it all out. It has worked flawlessly for the past year. I did notice a lot of dust in the motor before spraying it with wd-40
I did not oil or grease the shaft. If it acts up again - I'll definitely try that
Thanks

 

[jfreeth]

Thanks for the write up, really helpful.

There are a couple of latches that hold the glove box cover in place after you remove three hinge screws. Simply tugging on the cover may destroy them, so to avoid that, remove the right hand cover held in place by a single screw, this allows you to pull the hinge out a little and reach behind and pinch the latches. They are really flimsy, but kind of useful.

The brushes on the commutator produce a lot of debris and may contribute to the increased friction, so I flushed them out thoroughly using WD40. Then lubricated the bearings with penetrating oil, etc. The shaft end-floats a little, but something was still binding so I tapped lightly on the shafts with a hammer, both ends, then lubricated and spun the cage. There is still a little stiction before spinning, but not sufficient to stall the motor.

Note that when the switch is actuated to turn the fan on there is a noticeable delay, maybe a second or more, then a surge as if a starting capacitor kicks in. I haven't checked the voltage so don't know if that is the case but with a stalled DC motor normally the starting current would be very high, sufficient to blow the 30amp fuse, but did not. So maybe there is some clever MB electronics kicking in that protects a stalled motor.

Anyway, it's now working, we'll see for how long...

 

[irvingj]

Great write-up. No problems yet on my 2015, but nice to know. I've kept an air exchanger fan going for 30+ years by simply removing it once a year and putting a few drops of oil on the bearings. Lifetime lubed my ___!

 

[Ovrlnd_Trvlr]

Huge thanks to WindTrackMind for the details on removing the fan.

 

[levinro]

Here's how I suggest Removing the Glove Box: remove 4 screws location in green, one is on bottom of right side panel, then pull that right side panel straight off and away.
The three green screw locations at bottom of glovebox are inside the glove box of course, yes you must empty the glove box. Once those are away, the glove box drawer comes away. If this hinge ever fails, I plan to use nylon cloth webbing or maybe milk jug material as a replacement hing.
Remove the top 3 screw locations marked with orange next, then pull the glove box housing away from dash, removing the wire to the lamp and ventilation hose as you go.
Reinstall is simply the reverse.

This was super helpful to me, although I was a bit confused as I did not see the 3 bottom screws in the glove box. For anyone else that gets tripped up on this, here is the secret. When you open the glove box, there are 2 "stops" that must be pushed up (see picture) so that the glove box can fall all the way down, revealing the 3 bottom screws. After that, it is a piece of cake as described above.

 

[roady51]

To remove the Blower Fan motor, you might have to remove one screw at right that will allow the structure to give more clearance when you remove the motor.
Simply unhook the power to the blower motor, and twist the motor end CCW to remove. There is a plastic spring loaded friction at about 5AM on the dial, you can ignore it or pry it up a 1/8" to see if it allows it to twist easier.
Here's a pic of the motor and orange pointer to the spring keeper that I didn't have to pry to twist. And next to that, a pic of the dash with motor removed.

thanks for you photos . for my van the 'spring keeper' is at around 9 o'clock . I did have to slip a thin tool under it just to get it unlocked but it wasn't a difficult .

 

[thebitmaster]

SWEET MOTHER OF !@#@!#!@ THE SQUEAKING HAS STOPPED!!!

Thank you SO MUCH!!!