1998 W210 E300DT Bad Blower Regulator or Blower Motor?? How to tell - Benzworld.org

DieselNuts · 08-21-2007, 06:10 PM

Hello all,

I had the unfortunate experience of a dead blower fan motor, which apparently is a common feature of the W210. The climate display is responsive and I can hear flaps opening and closing under the dash, but I do not get any air blowing. The fan is dead. Apparently I've read that if the regulator is bad, the fan speed is about 1/2 speed no matter what setting. My fan is dead.

I find myself in a predicament. If I purchase the W140 blower regulator, and it turns out that the fan is bad, I will have to buy a new fan and another new matching regulator. (I think the cost of the new motor, regulator, and mounting bracket is more than $700.)

How do I tell if I have a bad motor or a bad regulator before I purchase the parts I need.

Any advice and suggestions are greatly appreciated.

Thank you.

**Matt L** · 08-21-2007, 06:28 PM

Connect power to the fan. You should already have +12V there, so you merely have to ground the lead going to the regulator. The fan should run at full speed if the motor is good.

DieselNuts · 08-21-2007, 07:15 PM

Thanks, I will remove the motor and will try to power it up, if it spins I change only the regulator.

Why was the whole blower regulator and motor redesigned??? Was the blower regulator redesigned because the old one failed often? If so, should I opt for the new version upgrade?

If I get the W140 blower regulator, how does it compare with the original W210 regulator in terms of quality? If they are the same, does that mean it is the same POS as the one that broke. I've seen original W210 regulators for sale on E-Bay, the one that is discontinued. Should I buy the original W210 regulator if I find it?

Thank you.

**Matt L** · 08-21-2007, 07:19 PM

I would recommend powering it up in place.

Of course, I don't know why the assembly was redesigned. Perhaps it cost them less per car for the newer parts.

As far as I know, the 140 regulator is electrically identical to your old one. Yours may have broken, but most of them don't and I wouldn't worry about it very much. Personally, I would buy a factory 140 regulator over a 210 regulator sold by anybody on eBay.

DieselNuts · 08-30-2007, 08:38 PM

I just finished up this job by using the 140 regulatory, which I purchased from Autohaus AZ, and I am totally happy now. The fan works great and I saved myself ~$450. The writeup on splicing the wires was very informative and easy to follow.

So the dead motor was indeed the blower regulator and not the fan in this case.

I ended up changing the charcoal and the regular filters, which added 15 or so minutes to the job.

peru9800 · 11-22-2008, 01:05 PM

I have the exact same problem and was not sure about going with an old w210 or a new 140 for the same reason, spend that money and then need a new w210 regulator and blower.

Can you tell me exactly what you ordered from autohaus az? a new regulator for a 1998 w140? do you have the exact part number? did you order the filters as well from them? can you provide that info as well?

thank you!

ttaylor · 11-24-2008, 10:58 AM

Wondering how you made out with this repair and acquiring parts from Autohauz AZ.
I have to make same repair and wondering which part is required.