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How to Repair a Heater Motor Resistor on a 1999 BMW Z3 2 5L

The heater motor resistor on a 1999 BMW Z3 2.5-liter roadster is integrated into heater motor itself. This resistor plugs into the front side of the motor assembly. The heater resistor is not repairable; it must be removed and replaced if it fails. This resistor allows the motor to spin at variable speeds, consequently allowing the ventilation system inside the roadster to blow hot or cold air at different speeds. A bad motor resistor will either allow too much or too little current in to the motor, severely limiting the variable fan speed function of the HVAC system.

Instructions

Removal

1

Pry off both wiper arm caps with a small flat-head screwdriver, then remove the wiper arm bolts with a ratchet and socket. Mark the position of the wiper arms in relation to the spindles with a small tube of white paint. Lift the wiper arm up so they are at a 90-degree angle to the windshield, then lift the arms off of the wiper spindle gears.

2

Disconnect the washer pump tubing from the air intake/heating grille. Open the hood, then pry out the plastic retaining clips on both ends of the air intake/heating grille with the flat-head screwdriver. Lift the air intake/heating grille up and away from the lower windshield area, detach the remaining washer pump hoses, and remove the grille completely.

3

Disconnect the wiper motors electrical harness connector. Remove the bolts holding the wiper motor and arm assembly to the inside cowl, using a ratchet and socket, then slide the entire assembly to the left in order to disengage it from the integrated hooks. Lift the assembly out of the vehicle and set it on the ground or on a workbench.

4

Disengage the clamps on the blower motor fan cover by pushing them to the left until the pop loose, then set the cover aside.

5

Locate the heater motor resistor, directly below the motor body in the center of the assembly. Pry the resistor out of the fan assembly with a flat-head screwdriver. Discard the old resistor.

6

Press the new resistor into the fan motor assembly until its fully-seated.

7

Reinstall the heater motor cover and re-fasten the covers retaining clamps.

8

Position the wiper motor and wiper arm assembly inside the cowl section and slide it to the right to engage the locking tabs. Reinstall the retaining bolts for the wiper motor and wiper arm assembly.

9

Connect the washer pump hose to the underside of the air intake/heating grille assembly. Position the assembly over the cowl area and connect the top washer pump hose to the air intake/heating assembly.

10

Reinstall the plastic retaining pins on the corners of the air intake/heating grille assembly and press them down until they are fully-seated. Reinstall the wiper arms into their original position and then reinstall the wiper arm retaining bolts. Reinstall the wiper arm caps and test both systems to ensure proper operation.

Posted by Unknown at 6:15 AM

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Labels: 1999, 2, 5l, a, bmw, heater, how, motor, on, repair, resistor, to, z3