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TR2/3/3A TR3 Wiper Motor

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mountainman

mountainman

Jedi Trainee
Offline
Been working on my wiper motor all morning and still no go. Here's what going on.
Took wiper switch apart and cleaned now working.
Hooked battery charger to wiper motor and it runs, but does not park.
Jump across switch,no run.
Checked voltage at posts#1,#2 on wiper motor results
key off
wiper switch off = 12.52 volts #1,#2

key on
wiper switch off = .23 volts #1,#2

key on
wiper switch on = .24 volts #1,#2

Can anyone please tell me what you think is wrong and how to correct it, as I am about to pull what little hair I have left out.
As always thanks so much.
Greg
 
Aloha Mountainman,

Just to help confirm you have it wired correctly here is the way it should be. Terminal #1 - Black wire to switch, terminal #2 - green wire from fuse block (power source) and additional black wire from motor casing screw to ground near motor. The other terminal of wiper switch is connected to the ground on the dash panel.
 

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Assuming the motor is connected properly, the next step I would suggest is to loosen the the three screws holding the wiper drive cover plate in place so you can move the parking control. With power to the motor and the wiper switch "on", rotate the dome and hopefully the motor will start. As I understand the operation of wiper motor with parking mechanism, the dash switch opens a path to ground for power to pass through the motor and run the motor. When the switch is turned "off", the path to ground is interrupted but an alternate path to ground is available through the orange wire to the parking switch and the motor frame ground connection. once the motor drives the mechanism around to the insulated "dead" area on the switch under the dome the alternate path to ground is now also open and the wiper stops in the parked position. This position is adjusted by either replace the wiper arms in the desired position or rotating the dome to achieve the desired parked position.

These motors are pretty robust. I once had a wiper blade jam under the windscreen frame and was not able to pull over and free it for several minutes. Turn off the wipers with the dash switch did not stop the power to the motor because of the parking switch. Once I got the arm free, the wipers started again, no damage to the motor and the fuse did not blow.
 
Take a look at this diagram.

wiper1.jpg


I made the connections bold so they are easier to see.

You have establish that the wiper motor is OK when connecting it to the battery charger.

The wiper motor is fed from a switched terminal on the fuse box. There should never be voltage at the wiper motor unless the ignition switch in ON. If there is voltage present all of the time, the circuit is not wired correctly.

The wiper motor has two terminals and an earth(ground)terminal.

When you turn on the ignition key switch, the green wire terminal at the motor becomes hot.

The black wire terminal is connected through the wiper switch to earth.

If you turn on the wiper switch, the wipers should operate.

If the switch is bad and you jumper the switch terminals the wipers should operate. If neither of these actions cause the wiper motor to operate, there is a bad connection in the black circuit, probably on the earth side.

Hope this helps.
 
That black wire shown that goes from the switch to the motor may actually be a green wire with a black tracer.

But be double-darn sure that the wire that goes to the dash switch is from a ground and not a power source.
 
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