NEED HELP: (Cab Electrical) Wiper Motor Wiring

[Boydness]

Here is the wirind diagram of the wiper motor connections and the crude sketch of the wiper motor that is under the dash of my truck.

Apparently I have a black wire from one of the terminals grounded to the top bolt (driver's side).
The "dark blue" cable (from the wiper switch) in a shared plug (with a yellow cable) is connect on one side of the wiper assembly.
And there are four terminals on the other side of the wiper assembly. The top one is grounded to the bolt as mentioned above. And the other three are currently unconnected.
I have a "light blue" cable (from the wiper switch) in a plug (with the jumper yellow cable from the "dark blue" & yellow plug).
And a free hanging single "black" cable/plug from the wiper switch.

Can anyone please tell me how there wiper motor is connected with the plugs? And if that black cable grounded to the bolt is suppose to even be there?


Boyd

[pjmoreland]

Here's how my truck is wired:
Yellow wire to 3.
Light-blue wire to 2.
Black wire to 1.

My wiring diagram looks like it should be wired like this though:
Light-blue wire to 3.
Yellow wire to 2.
Black wire to 1.

My wipers don't work, so maybe the light-blue and yellow wires are reversed on my truck. Hopefully someone else will chime in.

[Boydness]

Do you also have that second black wire from the top terminal to the bolt?

[pjmoreland]

no

[pjmoreland]

I just realized that my wipers work fine. It's my windshield washer pump that doesn't work. connect your wires like this and it should work:

Yellow wire to 3.
Light-blue wire to 2.
Black wire to 1.

You shouldn't need that extra black grounding wire because the grounds for the two wiper speeds and for the washer pump are supplied by the wiper/washer switch.

[Boydness]

Originally Posted by pjmoreland

connect your wires like this and it should work:

Yellow wire to 3.
Light-blue wire to 2.
Black wire to 1.

You shouldn't need that extra black grounding wire because the grounds for the two wiper speeds and for the washer pump are supplied by the wiper/washer switch.

Removed the "ground to the bolt" cable and wired it as you stated: Nothing

Could I have a bad wiper motor? How do I tell?

Appreciate all the help.

Boyd

[chickenwing]

My diagram shows the jumper yellow power wire to pin 2, lt blu to pin 3 and black to pin 1. Try that, if that does not work I would troubleshoot as follows:

Turn on key verify power from pin 2. If power, turn off key remove plug from switch, ohm switch pins to ground, should be no resistance. Resistance, clean switch mounting surface reinstall try again. Still resistance, bad switch. Switch good, remove wires from wiper motor and switch, ohm from end to end verify no opens. Ck good, then bad motor. You can bench test the motor by powering pin 2 and grounding pin 1 or pin 3.

[pjmoreland]

Considering all of the strange things you have found in your wiring, have you checked to make sure the connector is plugged into your wiper switch?

The yellow wire supplies power (12 volts) to the motor when you turn your ignition on.

The black and the light blue wires supply ground to the motor depending on which position the wiper switch is in.

There are two resistors inside the motor housing that give you the two speeds, based on which wire is providing the ground (black or light blue).

I'm 99% sure it's as follows:

Yellow wire to 3.
Light-blue wire to 2.
Black wire to 1.

That's how my truck is wired, and my motor works. If yellow and light-blue are reversed, the motor will not work.

You should be able to measure resistance between 1-2, 2-3, and 1-3. If there is infinite resistance (open circuit) between any of the pins, then there is something wrong with your motor.

[Boydness]

I know that I have 12V on the yellow.
And I visually verified that the plug was in the switch. I need to check the switch and verify everything else that you mentioned...
I will do that this evening.

Boyd

[chickenwing]

Am I just reading this wrong? Kinda photo mangled but it works.

[pjmoreland]

I think you are reading the schematic correctly chickenwing. I agree that the schematic looks like it should be wired that way, but the wiring in my truck disagrees with the schematic, and my wipers work. This is pretty strange. Maybe someone else can take a look under the dash.

[Boydness]

Originally Posted by Putter

#3 = Yellow
#2 = Light Blue
#1 = Black

If you haven't done so, you can unhook the harness at the switch and ground the black wire and get HIGH speed, ground the black AND the light blue together for LOW speed, and ground the dark blue for wash. (You will need to have the key on so the motor gets power.)

Here is what I got:
With the black lead (from the switch plug) grounded to the dash, the wipers moved and completed a whole evolution (elapsed time 4 secs, ran even after removing the ground after the start).
Black and Lt Blue grounded: Sparks, but no movement
Dark Blue grounded: Sparks and pump click

[chickenwing]

Well if Putter says it's yellow to pin 3 it must be so. He fabbed up the harness for my intermittent wipers!

Weird that the diagram is wrong...