W210 blower fan issues...

[Duckman999]

1998 E300 car.

I replaced my blower fan resistor 2 weeks ago as suggested by many online forums. Several people had said you would need to cut/splice, as I have an early car. The resistor came with 2 harnesses, and was a plug in affair. Blower worked immediately afterwards and all was well.

2 weeks later (yesterday), the blower fan is now doing the same thing, stuck on low/nearly off. With summer fast approaching I need to get this fixed ASAP.

Anyone have a suggestion as to what it could be? I'll order another blower fan resistor, but I'm curious if something else is causing these to fail, or perhaps it was just a crappy part? (It came labeled bosch)

[Matt L]

Check the motor by bypassing the regulator; ground the negative lead at the motor. It should run full speed.

Where did you get the part? Counterfeits are out there.

[Duckman999]

www.bmaparts.com is where I got it

BS part of it is they want to charge me a "return charge" and a "handling fee". I'll need to confirm it went bad first, but that's bad biz if you ask me to charge a customer for a defective part (if it is indeed the part that is bad).

If I understand the way it works, and what you posted, the resistor simply varies the resistance through the ground...so if I run it straight to ground it'll run full speed?

I'll jump the thing and report back...

[Matt L]

It's not actually a resistor, but yes, it allows current to flow from the motor to ground. If you ground the motor lead, the motor will run at more than full speed.

[Duckman999]

Opened it up, it's not the resistor pack.

I wiggled the power connection, and it came to life. It seemed like it was imbalanced or wobbling a lot. After careful inspection, it seems like the motor either is cast into the housing in a tiny spot, or was grounding/arcing to that spot.

I wiggled the motor around a bit, something seemed to free up, and it spins free now/works great.

I'm guessing it's a temp fix, I need to source a new fan now