Removal, operation check and installation of the heater and air conditioner (BMW 5 Series E28)

Removal

Retro models (E28) use two separate blower motors: one for ventilation and heating. And one for air conditioning. Modern models (E34) have a single blower motor. Removal and installation of the single blower motor, as well as the motor for ventilation and heating on retro models are described below. Removal and installation of the blower motor for air conditioning on retro models is described in Section Removal and installation the air conditioning battery/dehydrator of this Chapter.

If your vehicle's radio is equipped with an anti-theft system, make sure you enter the correct code before disconnecting the battery.

If the instrument cluster displays the wrong language after connecting the battery, refer to Section Anti-theft audio system and instrument cluster language, which describes the procedure for installing the required language.

1. Disconnect the negative battery cable.



2. The blower motor is located behind the bulkhead, under the access panel. Loosen the panel mounting screws at the front...



...and the mount on top holds this panel in place



3. Disconnect or cut the plastic fasteners holding the wiring to the panel and move the wiring to the side.

4. Remove the panel.



5. Loosen the supercharger housing retaining clip and the clip holding the supercharger motor.





6. Disconnect the wiring and remove the blower motor.

Examination

You can test the supercharger motor by applying battery voltage to the motor terminals using the jumper cables provided with the jump start kit (make sure the fan blades do not hit anything when rotating). If the blower motor rotates the fan blades at high speed (this test is designed for its high speed operation), then it is in good working order. If the motor does not work, or works slowly or noisily, replace it.

If the fan blade assemblies need to be removed, mark their positions on the shaft. These assemblies were balanced at the factory, and if they are not installed in exactly the same position relative to the shaft, this may result in excessive noise during operation or premature bearing wear.

Installation

Install in reverse order.

It may be necessary to rotate the blower motor to properly install the retaining clamp.