Blower motor ?

[J. M. van Swaay]

1994 E500 125K miles

Blower motor intermittent at first, then failed. Motor had been replaced with Behr/Hella unit 1.5 years ago so suspected regulator/controller. Verified 12 v at regulator connector red lead, 1.3 v at regulator control lead with fan push button on low, 7.6 v at control lead with fan push button on high. Believe this is normal and verifies function of dash control unit. Connected 12v battery charger directly to fan—fan spins but draws 10 amps (maybe more but charger amp scale tops out at 10). Fan seems difficult to turn by hand, can get maybe 1.5 to 2 turns with max manual spin effort. Anybody know what normal current draw might be? or if that much “spin drag” is normal? Beginning to think motor bearings are just to stiff for the amount of current supplied by regulator. Ferris, Anyone?????

 

[gsxr]

Sounds a lot like a failed regulator. On max speed, the blower motor will pull ~25A or so. Difficult to measure without some creative temporary wiring and a clamp-style ammeter that will read high enough.

The blower bearings are kinda stiff, ~2 turns by hand seems normal.

 

[gerryvz]

90% likely it's going to be your regulator.

 

[Jlaa]

1994 E500 125K miles

Blower motor intermittent at first, then failed. Motor had been replaced with Behr/Hella unit 1.5 years ago so suspected regulator/controller. Verified 12 v at regulator connector red lead, 1.3 v at regulator control lead with fan push button on low, 7.6 v at control lead with fan push button on high. Believe this is normal and verifies function of dash control unit. Connected 12v battery charger directly to fan—fan spins but draws 10 amps (maybe more but charger amp scale tops out at 10). Fan seems difficult to turn by hand, can get maybe 1.5 to 2 turns with max manual spin effort. Anybody know what normal current draw might be? or if that much “spin drag” is normal? Beginning to think motor bearings are just to stiff for the amount of current supplied by regulator. Ferris, Anyone?????

Your blower motor sounds perfectly fine. See here for a video that describes how much drag is normal on a NEW Behr/Hella service blower motor (albeit for the earlier 1993 500E).

Blower Motor | Heating and Cooling (Interior HVAC systems)

Anybody bought and installed a VDO blower motor before? I know they're an OEM supplier and on "The List". Wasn't familiar with them for blower motors. Usually you find something from Behr or Bosch...which I did...but at a higher price. The VDO blower motor was the best price. This is for...

www.500eboard.co

 

[J. M. van Swaay]

Is there a way to ”test” the regulator? I do see 12v at the blower motor leads when the hvac control high fan button is engaged but I have no idea how many amps the regulator can deliver....

 

[J. M. van Swaay]

I had ordered a new regulator prior to disassembling.... maybe I’ll just try it

 

[Jlaa]

Is there a way to ”test” the regulator? I do see 12v at the blower motor leads when the hvac control high fan button is engaged but I have no idea how many amps the regulator can deliver....

Start here: OWNER - a777fan (E420) | Owners and Their Cars @a777fan just went through this. The blower motor regular is an active part (transistor) so its going to be really hard to bench test .... its not a passive part like a regular old resistor. Best way to test it is as @gsxr does and just plug it in probably. If you end up buying an MB-branded regulator, try parts.edhicksimports.com. They have good pricing.

 

[J. M. van Swaay]

Just watched the video... the manual spin effort response on my blower is very similar to that depicted in the video. I’ll install the new regulator and report back...

 

[a777fan]

+1 on Ed Hicks. No half off shipping, but spee-dee service, and lower prices than the 'other guys'.

 

[geraniumtr]

Folks, I believe the factory blower regulator for a dust filter equipped W124 is no longer available. Recently I had to replace mine (94 E320) and dealer said NLA. Part for my car is 124 821 21 51. E320 and E500 use same part I’m assuming. I purchased a Kaehler part from FCP who was a few bucks cheaper than the other guys.
Just an installation note—- the heat sink portion is bonded not screwed to the regulator so you have to remove the entire unit. Remove the top portion of the plastic cradle, wrestle out the old regulator, install new unit.

Regards,
Peter Weissman

 

[gsxr]

Hmmm. I wonder if this went recently NLA, or was just temp OOS? Classic shows "available", but it may be outdated...

https://partssearch.mercedes-benz-classic.com/parts/A1248212151?tt=manual

https://parts.edhicksimports.com/oem-parts/mercedes-benz-hvac-blower-motor-resistor-1248212151

 

[a777fan]

It's still available. I just ordered one, and received it from Ed Hicks. Just installed it this past weekend.

 

[gerryvz]

Indeed, both MB Classic and MB Annapolis are showing the resistor as available. I am going into the MB Annapolis parts department in the next hour, and will personally check availability via Paragon with the parts manager.

The facelift US-spec E320s and E500s/E420s do indeed share the same regulator.

 

[kwontumspeed]

Holy $300 for a regulator!

My low speed blower speed has quit, without pulling off the motor for testing, all indication points to the regulator. But the price. Oy!

 

[a777fan]

Holy $300 for a regulator!

My low speed blower speed has quit, without pulling off the motor for testing, all indication points to the regulator. But the price. Oy!

only ~270 at ed hicks

 

[gsxr]

Keep in mind the p/n above (124-821-2-151) is for FACELIFT models only, aka "with dust filter". And yep, it ain't cheap... and ain't fun to replace either.

 

[Jlaa]

only ~270 at ed hicks

@a777fan just curious - Ed Hicks' prices are really good. That said, did they charge you "Full PartsRev Estimated shipping costs" or did they adjust shipping costs after the "estimate"?

thanks.

 

[gerryvz]

Ed Hicks' shipping charges (the UPS prices quoted ... remember that MBUSA and dealers DO NOT use UPS, they exclusively use FedEx for all domestic US shipping per corporate contract) are less for the same part as MB Annapolis. For this part Hicks quoted me about $16, and MB Annapolis (for a local shipment) was something like $23. Of course I pay zero by special arrangement.

The Hicks price for the regulator is also about $16 less than MB Annapolis, as well. And MB Annapolis is one of the better priced RevParts vendors out there (better than MB Naperville, for example). For me the Hicks would be about a wash, because the shipping cost would be almost exactly what the difference in base price would be.

Don't know if Hicks charges sales tax or not -- typically the RevParts dealers don't charge sales tax for out of state orders, but don't know how much longer that will last per Federal regulations. I have to pay 6% MD sales tax, but I get a local human throat to choke.

 

[Jlaa]

Ed Hicks' shipping charges (the UPS prices quoted ... remember that MBUSA and dealers DO NOT use UPS, they exclusively use FedEx for all domestic US shipping per corporate contract) are less for the same part as MB Annapolis. For this part Hicks quoted me about $16, and MB Annapolis (for a local shipment) was something like $23.

Are you saying that Ed Hicks quotes you UPS shipping costs? Ed Hicks quotes me FedEx Ground costs. Interesting.

 

[gerryvz]

Here's what I see:

Ed Hicks Imports:




MB Annapolis:

 

[Jlaa]

Hmmm. I see the exact same thing and prices from Ed Hicks when shipping to San Francisco CA.

BTW This is what I see from SF Mercedes Benz -- SFBenzparts.com. I do local pickup from them so that I don't have to pay shipping, only sales tax. Their prices are competitive since I don't pay shipping. Its actually the same price as your Annapolis except for the local sales tax.

 

[geraniumtr]

Gerry and others, update on part availability...just called my dealer here in upstate NY and yes the facelift regulator is indeed in stock in the US although it wasn’t when I tried to order one about a month ago. System shows 6 pieces on the shelves.
Regards,

Peter Weissman

 

[gerryvz]

I just checked with MB Annapolis in person 30 minutes ago. They confirmed, via their Parts-b-Gone system, that there are six in stock in the US, most being in the Robbinsville, NJ warehouse.

 

[a777fan]

@Jlaa and @gerryvz you guys have already figured this out, but yes. There is no discount from Ed Hicks. They will charge what the checkout page indicates.

Even with this, they still ended up beating Naperville on the total out the door.

 

[gerryvz]

It is possible that I can get a better deal with Ed Hicks because it doesn't look like they are charging any sales tax, whereas I am paying 6% sales tax. That said, the 6% is worth it to me to have someone local to deal with.

I feel sorry for you guys in Seattle who (from what my Mom says) are paying pretty much 10% sales tax these days.

When I was growing up in the Seattle area, sales tax was 7.25%. It was 8.25% in my county in Texas. Man, that's high enough !!

 

[gsxr]

Totally agree about the small premium for a local transaction. But very, very, very few people on the forum are fortunate enough to live within 1 hour of any dealer that has Annapolis-level pricing with free pickup. Most of us are trying to find a place that will ship without gouging on ship costs.

 

[a777fan]

Indeed. Ed Hick's does not add your states sales tax to your total. I think that is becoming rarer and rarer these days.

10% is a bit of a tough pill, although we have still avoided an income tax. Not sure how much longer that will last though. Every time I drive down the highway or local roads I can't really argue with the need to add more capital into the system. lol.

 

[gsxr]

Every time I drive down the highway or local roads I can't really argue with the need to add more capital into the system. lol.

I would gladly pay more taxes if the revenue was actually used to PROPERLY improve infrastructure. Based on the continuous road "improvement" debacles in this area, I'm nearly certain that the former would never result in the latter. They'd just find new ways to do it wrong with more money.

 

[gerryvz]

Totally agree about the small premium for a local transaction. But very, very, very few people on the forum are fortunate enough to live within 1 hour of any dealer that has Annapolis-level pricing with free pickup. Most of us are trying to find a place that will ship without gouging on ship costs.

Well, I guess that more forum members need to be moving to places like Corpus Christi, and Wash DC/Annapolis so that they get the free pickup and lower pricing

Wait ... maybe not.

 

[a777fan]

I would gladly pay more taxes if the revenue was actually used to PROPERLY improve infrastructure. Based on the continuous road "improvement" debacles in this area, I'm nearly certain that the former would never result in the latter. They'd just find new ways to do it wrong with more money.

Agree. It is pretty unfortunate that there doesn't seem to be a way of transparently communicating about required cost for various civil improvement projects. The communication that currently exists doesn't seem to do a good job of explaining 'here is what you are going to get for this amount of money, and this is why'. Either that or I am missing where/how this information is being shared.

It makes it very hard to justify or support asks for additional funding, all while our infrastructure continues to erode.

 

[a777fan]

Well, I guess that more forum members need to be moving to places like Corpus Christi, and Wash DC/Annapolis so that they get the free pickup and lower pricing

Wait ... maybe not.

Any houses down the street for sale honch?

 

[gerryvz]

Any houses down the street for sale honch?

Actually they just started breaking ground this week on a new one. Just took these photos while out walking the dog an hour or so ago. About 3 houses down and across the road. The plans are showing a ~$750-850K house to be built. Probably not done until next summer.

 

[J. M. van Swaay]

Replaced the regulator, everything now functions correctly. A side note, I have previously used the Kaehler part, I don’t like it because it is very difficult to get it into the cavity below the blower motor. As mentioned elsewhere, the electronics module can not be separated from the heat sink.

I choose to take a chance on the the cheap chinese unit branded SKP, about $48 from Rock Auto (link). The electronics module on this unit is screwed to the heat sink. Installation is much much easier because you can remove the module from the heat sink and then fasten it to the existing heat sink with the two screws. Time will tell if this module proves reliable.

I don’t think it will be any worse than the Kaehler unit, I have had two of them fail within a year of installation.

J. M. van Swaay

 

[gsxr]

I don’t think it will be any worse than the Kaehler unit, I have had two of them fail within a year of installation.

OUCH. Two different Kaehlers failed within a year? That's not good.

And this was with a new Behr/Hella motor? I expected better. Wonder if that's related to why FCP doesn't carry regulator 1248212151... too many warranty claims?

 

[gerryvz]

I have said for MANY years that the Kaehler regulator units ARE NOT of good quality, and that folks with the late cars should ONLY buy the only alternative, which is the factory regulator.

 

[a777fan]

For future reference, which might already be obvious to others who read this thread, the factory unit is also able to separate from the heat sink. Thats how I did it. Used the old sink and screwed on the new resistor with some new heat sink paste.

 

[Jlaa]

...Installation is much much easier because you can remove the module from the heat sink and then fasten it to the existing heat sink with the two screws. Time will tell if this module proves reliable.

...For future reference, which might already be obvious to others who read this thread, the factory unit is also able to separate from the heat sink. Thats how I did it. Used the old sink and screwed on the new resistor with some new heat sink paste.

Does the magic screw not work on the facelift models? Is there no magic screw on the facelift models?

Blower Motor | Heating and Cooling (Interior HVAC systems)

@RicardoD I cannot remember what I read to arrive at this hypothesis: The regulator is basically a big power transistor. Whatever is in there --- BJTs/MOSFETs/Whatever --- there is enough current that goes through there (depending on the voltage on the yellow wire that feeds it) that the...

www.500eboard.co

 

[a777fan]

hmm. I’m sure it does, but I don’t think I craned my neck down and around enough to check when I had everything apart.

 

[gsxr]

IIRC, the magic screw was deleted from facelift models with the dust filter. But, next time I have one apart I'll double check.

 

[gerryvz]

100% correct. There's no magic screw on the facelift cars.

This is why late model owners are screwed ... you either have to go Kaehler, or go Factory ... or go home.

Pre facelift folks have options.

 

[Jlaa]

100% correct. There's no magic screw on the facelift cars.

This is why late model owners are screwed ... you either have to go Kaehler, or go Factory ... or go home.

Pre facelift folks have options.

 

[J. M. van Swaay]

I’m not convinced that the MB regulator is a good gamble. At $350ish I’ll take my chances with the $48 SKP Chinese unit. The difference is about $300... I’ve done this job at least a half dozen times over the 15 years I’ve been maintaining these old 124s. I can do it in about 90 minutes..... 90 minutes, $300, you do the math.... I know I won’t install any more Kaehler units, jury’s still out on the SKP unit. I’ll let you all know if/when it fails...

My opinion only...

J. M. van Swaay

 

[gerryvz]

To me, $300 is worth not having to hassle with the regulator for the next 10-12 years.

 

[J. M. van Swaay]

Just curious, has anyone experienced an early failure with the genuine MB part? If the reliability is indeed good enough that 10-12 years of trouble free operation can be expected, I may have to change my thinking....

 

[a777fan]

No early failure here. Mine was still going strong 26 years later until my PBU melted and took out the regulator.

 

[gerryvz]

I have owned a number of W124s. I have only had to replace one regulator, on the former white 1995 wagon with ASR that I once had. I never did a HOW-TO for that, and I should have at the time.

My 1995 G-wagen regulator went out, but it is shared with the late W123 and early W124 models (non-ACC), and is easily located in the air intake box below the windshield. As shown here: HOW-TO: Replacing G320 (W463) Blower Motor Regulator | G-Wagen Models

 

[gsxr]

I suspect a decent number of 94-95 regulators are partly failed, and owners don't realize it. I've had several 94-95 cars where the high speed fan isn't high enough. The only way to test is measure current draw with a clamp-type DC ammeter. Low speed pulls ~7A, high speed should be 25-28A. With the "partly failed" regulator, high speed is only medium speed, pulling 15-18A. Is it worth $300+ to get full speed? You decide...