The switch itself is the determining factor if a motor operates as a variable speed or a three speed. They build the same, they test the same. I build on my bench using a 3 speed switch because it's what I mounted to my bench. If I ship that same motor to someone who has a variable speed switch, then the motor will operate as a variable, although it operated as a 3 speed when it left my shop.
Bench Test Procedure for a 3 speed/variable speed:
If you do not have the proper functions, 99% of the time it is a ground problem. If you experience this, first run a ground wire from the metal housing on switch to the pin switch for dome light in drivers door jamb. Run switch again. If you still have a problem run a ground wire from the wiper motor ground strap to the negative battery post. Run switch again.
If you still experience trouble:
(1) Disconnect motor leads at bulkhead disconnect. Connect jumper wire from battery positive terminal to brown and red leads in bulkhead disconnect. Connect a second jumper from the green lead to ground. (The ground circuit is completed through the car body). The motor should run continuously. Disconnect leads.
(2) Connect jumper wire from green lead to brown lead. Connect red lead to ground. Connect third jumper wire from battery positive terminal to blue lead. The wiper should run to the park position. CAUTION: Motor can be damaged if not wired correctly
Bench Test for your Switch:
You can use this to test your switch with an Ohm meter.
Wiper Switch Wiring and Testing
Color Wiring:
A = Brown w/ White
B = Pink
P = Blue
W = Brown
F1 Red
F2 = Green
B/U = No Connection
B to B/U = B voltage in across the internal circuit breaker. Always on no matter what speed or off position to B/U. B/U Voltage After Circuit Breaker
The following connections should all be reading 0 ohms, except as noted, when active. Any connection combination not mentioned should not show a reading.
In the OFF position:
B to P
A to F2
F1 to Housing Ground
In On Low through High speed positions:
B to F1 {(0 Low) to ( 25 High)}
A to F1 {(0 Low) to ( 25 High)}
B to A
F2 to Housing Ground
Washer Motor On No Reading In The Off Position
B to W
A to W
F1 to W
(My thanks to Jim aka Slotts, at JS Restoration for the switch test procedures)
If you're still having problems, shoot me an email, send me a pm or grab a phone and give me a call. Hopefully we can walk through this and get you back up and running.
