Heater blower only working in position 4
Moderator: martauto
Hi bmw e30 325 auto suddenly heater blower only works on the fastest speed never been noisy or anything just stopped working at slower speed and ideas what the check is it easy to replace the heater motor and from engine bay or from inside thanks
- Bonymaenjack
- E30 Zone Regular

- Posts: 855
- Joined: Fri Nov 06, 2015 11:00 pm
- Location: Swansea
Not a difficult to do , access to it is through the engine bay . Sounds like maybe a resistor has failed ?
https://www.e30zone.net/e30wiki/index.p ... nly_on_Max
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
If the fan spins freely, as it might, from what you say, then the problem is either with the rotary switch or the resistor pack, and it's unlikely to be the switch.
There is a bimetallic thermal cut out built into the resistor pack, and if you're lucky, cleaning the contacts of this may effect a cure.
Unfortunately, heat from the contacts making a poor connection before it totally fails, often melts the plastic, writing the pack off.
There is a bimetallic thermal cut out built into the resistor pack, and if you're lucky, cleaning the contacts of this may effect a cure.
Unfortunately, heat from the contacts making a poor connection before it totally fails, often melts the plastic, writing the pack off.
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Freeing it up with WD40 or similar, and then calling it a day, as suggested in the wiki, will be a short lived cure. The bearings of the motor are porous bronze, and need a good dosing of light oil if they are to remain healthy.

