3 speed wiper motor, 2 speed switch

[Robbie]

Recently purchased 1970 GTX, equipped with what seems to be original 3 speed wiper motor. Also what seems to be unmolested dash with 2 speed switch. Wipers do not work, ran a jumper from battery to motor and got movement.
Will a 3speed motor function with a 2 speed switch?

 

[dadsbee]

No, you need a 3 speed switch and the extra brown/w wire should be already in the dash wiring harness to use it.

How the switch gets wired is shown in this picture

Test that your motor functions properly first:

Bench testing procedure.


Test #1(Hi speed)


Connect jumper wire from motor case to battery ground.
Connect second jumper wire from battery positive to BROWN lead.
Motor should run hi speed continuously.


Test #2 (Lo speed)


Connect jumper wire from motor case to battery ground.
Connect jumper wire from GREEN wire to battery ground.
Join BROWN and RED wires together and connect a jumper wire from battery positive to them.
Motor should run at slower speed.


Test #3 (Park)


Connect jumper wire from motor case to battery ground.
Connect jumper lead from GREEN to BROWN wire.
Connect jumper wire from red wire to ground.
Connect jumper wire from Blue wire to battery positive.
Motor should reverse and park.

 

[Robbie]

Thanks ran the checks, all worked. During the low speed check my cheap jumper got hot.
My in dash switch does have 3 positions besides off. My bad.
With ignition key on I checked for power at firewall (bulkhead?) the terminal that connects to Brown wire had current, wiper switch off. Is this correct?

 

[Robbie]

Pulled switch , no continuity between B and B/U in any position