‘3/76 Wiper Motor wiring......

[tls3601]

So I recently acquired a wiper motor and am wondering if any of the experts can tell me what wire is hot. Blue wires, one is red, one is black, one is yellow and one is just plain blue. Motor not working. Pics below:

Also what size and pitch screws are needed to mount to windshield body? Many thanks mud brothers

 

[tls3601]

Anyone? Maybe @Coolerman will chime in?

 

[tls3601]

Bump

 

[RstBckt]

M6x1.00
Go to pick n pull or whatever you have in your area and pull something off a car to buy. While your at it find the newer Toyotas and unscrew a pile of bolts. They don't care how many fasteners you're taking home. Or order some stainless chinesium fasteners from Amazon.

Per the trusty Haynes manual diagram (btw the FSM's are available on Mud for download for freeeeee):
LW light blue and white is the stop cam to ground
LR light blue and red is Low ground
LB light blue and black is High ground
L light blue is positive at the turn wiper fuse

This is for a 78. Word to the 78's

 

[tls3601]

M6x1.00
Go to pick n pull or whatever you have in your area and pull something off a car to buy. While your at it find the newer Toyotas and unscrew a pile of bolts. They don't care how many fasteners you're taking home. Or order some stainless chinesium fasteners from Amazon.

Per the trusty Haynes manual diagram (btw the FSM's are available on Mud for download for freeeeee):
LW light blue and white is the stop cam to ground
LR light blue and red is Low ground
LB light blue and black is High ground
L light blue is positive at the turn wiper fuse

This is for a 78. Word to the 78's

Much appreciated sir, I am better color codes are identical for the ‘3/76. Will be working on it this coming weekend. Do those bolts that attach it to windshield frame ground the unit? Thanks Tom

 

[RstBckt]

LW, LR, LB are the grounds that run back to the switch. The switch is grounded. Through the white w/ black stripe wire and possibly through the dash. The white with black stripe wire has about the cheesiest connection in the switch as its loosely crimped to the housing.
On mine I want to redo it as I think the connection has become insufficient.

 

[RstBckt]

Make sure the power is off to the blue wire, key off should be sufficient as wipers don’t run without key on. Ohm the L* wires with the switch in appropriate positions to test ground contact. Or meter on voltage, power on all blue wire, ground to each L* wire at appropriate switch positions to see close to battery voltage.

 

[tls3601]

Getting into it this AM. Should the motor turn freely, this one does not.

 

[RstBckt]

If you’re trying to spin at the output shaft, no. You’d be trying to backdrive a worm gear.

 

[tls3601]

Is it possible juice needs to get to two of the pins on the motor? Tried juicing each connector and got nothing but did get a brief short.

 

[RstBckt]

All blue wire gets the koolaid, ground the blue and black and it should go whir. That's high speed. Don't fry that motor as they are a rare commodity. FSM schematic:

 

[tls3601]

Thanks so much for this info. Electrical is in no way my strength.

 

[tls3601]

So essentially the motor must be bolted up to the frame for it to run? That is be grounded?

 

[RstBckt]

No, that wouldn't be a great design as you would be relying on contact of motor housing to plate, plate to windshield frame, frame to hinge, hinge through pin... You get the idea.
The ground is through the wires. There is always positive on the all blue wire whenever the key is on (unless fuse is blown). Then the switch grounds the motor through the other 3 wires. Which ground is chosen depends on one of the 3 positions: High, Low, or Off. Yes off is still grounded but there is an interrupter in the motor unit. Inside the gearbox of the motor unit there is a contact which loses connection at bottom stop or park (whatever you want to call it). So if you turn the motor to off it will continue to run (still grounded) until the wipers hit park then it loses connection, connection being ground. The ground is through the switch itself.

 

[RstBckt]

I think the way you are looking at this is the motor will not run until positive is connected. Which is the way most humans think. Like how house wiring is. "The light bulb is grounded, always, and it turns on when I flip wall switch and it gets electrons flowing from the HOT wire."

In this case as with a lot of electric components it's the opposite. Hot is always present, when key is on, and ground through the switch makes stuff go.

 

[tls3601]

M6x1.00
Go to pick n pull or whatever you have in your area and pull something off a car to buy. While your at it find the newer Toyotas and unscrew a pile of bolts. They don't care how many fasteners you're taking home. Or order some stainless chinesium fasteners from Amazon.

Per the trusty Haynes manual diagram (btw the FSM's are available on Mud for download for freeeeee):
LW light blue and white is the stop cam to ground
LR light blue and red is Low ground
LB light blue and black is High ground
L light blue is positive at the turn wiper fuse

This is for a 78. Word to the 78's

Well the M6X1.0 is too big, could the motor mount bolts be an M5, same pitch? I am missing the bolts.

 

[tls3601]

Turns out the wiper washer squirt switch works as it powered the little washer pump motor I got from @fj40Matt so I will assume the other switches probably work as well. But, if I am reading what you said correctly the mounting bolts for the wiper motor DO NOT ground the unit. Electric is NOT my strong suit. Thanks

 

[tls3601]

Wrong Matt @ToyotaMatt

 

[RstBckt]

You’re on the right track. Check for voltage on the all blue wire at the wiper. So ground lead on multimeter connected to negative side of batt and positive in all blue with key on. If that’s good then start checking neg batt to other wires with switch in other positions for continuity

 

[Coolerman]

Bench test the motor BEFORE you do any mounting. Apply +12V to the solid blue wire and ground either the Blue/Black or the Blue/Red. If the motor is good, it will run on the bench. Be careful! These little motors have a LOT of torque...

The wiper motor itself will be grounded to the windshield when mounted BUT, in order to run, the wiper SWITCH must be well grounded to the dash! If the washer motor runs when you turn the switch knob, the switch is grounded enough to run the wiper motor.