electrical and ignition How To Wire 3 Wire Wiper Motor To Switch

[esty]

how do we wire to the dash switch and relay...motor tested with jumper, it does work

 

 

what's got us stump'd is the brn/blk wire from the signal stalk and the grn/blue wire from wiper switch are both hot with key on...do 2 hot wires get connected to the relay

[im3crazy]

So I know the right wire diagram, what year is the 02?  Stock wiring, or wire harness upgrade??

Thanks

 

[esty]

sorry...my bad...here's another thread with everything needed

 

http://www.bmw2002faq.com/topic/152813-testing-switches/

 

1969 with stock, all original wiring...no mods or additions.... AFAIK

Edited April 17, 2014 by esty

[im3crazy]

Thanks.  Here's a detailed description of the wiring and what functions are related to each terminal.  This will help if troubleshooting.

 

The relay is a timer relay.  When stalk switch closes momentarily (brn/blk) it grounds terminal 31b on the under hood relay.  This does two things (1) it starts the washer motor, and (2) it heats up the curved strip in figure 18 in the wire diagram. The strip expands and connects to terminal M triggering the Wiper Motor thru terminal 53 (BLK wire) for about 5 seconds.

Normal operation: Power is supplied from fuse #6 (YEL/BLU) wire to + marked terminal on dash mounted switch, Figure 23 wire diagram; note this wire also leaves this terminal to power other devices from the dash switch not related to wiper.

Two wires provide High or Low operation; YEL (low speed) wire from terminal 53b to corresponding  53b on wiper motor; and BLK from switch terminal 53 to same 53 terminal to motor (center conductor); 53a on switch is + power from fuse #6 YEL/BLU (this connection is the single connection on one side of dash switch in case you can’t see the terminal marking).   Note that the wiper motor also has a 53a terminal that gets the same power from fuse #6 , also YEL/BLU.  This allows the motor internal contacts to “Park” the wipers in the correct position when the switch or the relay power is turned off.  This is often the source of confusion on setup, and frequently this contact set in the wiper motor faults.  This fault can result in a run-on motor, or no parking.

Lastly, the wiper motor’s 4th wire is a ground BRN (grounds and negative connections nearly always are BRN).  Please make certain this is grounded well (shares ground with the heater blower motor ground point).

 

I've attached a wire diagram confirming yours.

bmw2002-usa-early pre71.pdf

[DRedman]

The reason you are getting 12v for both wires is because the switch is inactivated.  When you pull the switch the brown/black wire (31b)will be 0v or ground since you will ground one side of the delay relay coil winding. Terminal 15 gets it voltage from the same wiring connector that feeds the wiper motor(53A) from fuse 6.

Wiper motor terminals 53 and 53b voltages are dependent upon the wiper switch settings.