The BMW Z3 wiper and washer system consists of the following:
- Windshield wiper motor, arms and blades.
- Tailgate window wiper motor, arm and blade (Coupe).
- Washer fluid reservoir with fluid level sensor in engine compartment.
- Windshield washer pump in fluid reservoir.
- Headlight washer pump in fluid reservoir (if equipped).
- Tailgate window washer fluid reservoir in right rear, behind trim panel (Coupe).
- Tailgate window washer pump in fluid reservoir (Coupe).
- Heated windshield washer nozzles.
- Headlight washer nozzles in front bumper (if equipped).
- Tailgate window washer nozzle (Coupe).
- Wiper and washer switch at right side of steering column. Switch controls wiper intervals and other functions via the General Module (GM V).
- Rain sensor at top of windshield (if equipped).
The windshield washer pump is responsible for pressurizing and pumping washer fluid to the windshield; a separate pump supplies washer fluid to the headlight washer nozzles. The washer pumps and pump sealing grommets can leak. When left unrepaired for some time, washer fluid ruins the electrical connector leaving your windshield washer pump(s) inoperative. It is important to deal with the fluid leak immediately; replace the washer pump and grommet together.
In this tech article I will go over how to test and replace the windshield washer pump.
To avoid marring the trim or paint, work with a plastic prying tool or wrap a screwdriver tip with masking tape before prying out trim panels, switches or electrical accessories.
Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches.
Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Do not work on your vehicle if you feel the task is beyond your ability.
Vehicle models change and evolve as they grow older, so the vehicle shown in our illustrations may vary slightly from yours. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.
Remove the plastic flathead reservoir fastener (green arrow), then lift washer tank up to access washer pump.
This photo shows the backside of the electrical connector. The purple/black wire is the battery volt feed, it is hot with the key ON. The brown wire is the ground wire. The ground is activated when the pump is activated. If you were to test these wires with the washer inactive, battery volts would be present on the purple/black with the key ON. The brown wire would only have ground when the washer button is pressed. Always check and confirm the wiring on your vehicle using an up to date wiring diagram.
Disconnect electrical connector (green arrow) by pressing release tab and pulling off.
Connect a test light or DVOM across washer pump electrical connector terminals. Press washer button, test light will light. DVOM will read Battery volts (voltage the battery is at, 12 volts for example).
Keep in mind, a test light may light with a low supply voltage. I suggest load testing using a test light and a DVOM. Connect DVOM across washer pump electrical connector terminals and take a reading, it should read battery volts when washer button is pressed. Then connect an incandescent bulb style test light to battery ground and touch the test light probe tip the positive wire you are back probing with DVOM. Your reading should hold steady, a maximum drop in voltage of 0.5 volts is OK. Anything more, like shown here in this photo is a problem. The connector was faulty. The initial reading was 12.1 volts, when loaded it dropped to 1.3 volts. You can test the ground of the pump the same way. Connect your DVOM to the brown wire at connector, then battery negative, you should have a reading close to 0.0 volts. Then connect an incandescent bulb style test light to battery positive (you can use jump start stud under hood) and touch the test light probe tip the positive wire you are back probing with your DVOM at the brown wire. The voltage reading should change more than a 0.2 volts.
This photo shows the same test as above, but with a good connector. You can see when loaded the voltage is holding at battery volts. (note: there is a vehicle power supply connected to vehicle) If you find a problem with the connector, replace the pigtail with new. Cut the harness back enough to find good, clean wire, then butt connect and seal harness. If you need to replace the washer pump, just pull it straight out of the reservoir. Be prepared to catch the leaking fluid in a drain pan. Always replace washer pump and grommet if you find an issue with the connector, as a washer fluid leak likely damaged the connector.