Front Windshield Wiper Issue

[subarufan]

So I looked through the forums and did not see anyone else with this issue so was hoping you guys could point me in a direction. Its on our 2005 Outback with 50K miles and been garaged all its life (seldom used).

When I start the car I have an intermittent issue with my front wipers. I move the stalk control to either of the 3 settings (inter/lo/high) and get no action from the front wipers but when I select for the rear wiper that one works. When doing this in Park I can hear the engine RPM drop a little each time i move the stalk from OFF to any of the settings so there must be voltage getting to/from the stalk.
THEN when i turn off engine and move the key to OFF then go restart the car the front wipers work again.

Does this sound like a ground issue? I have the Factory Wiring Diagram but could use some guidance. Find it hard to imagine its something significant as these components have seldom been used over the years.

Thanks fellas.

[plain OM]

It doesn't seem like a ground issue.

Instead, it could be the motor. The contact between the brushes and the rotor commutator could be contaminated/dirty. After being off for a long while, the bad contact won't allow enough current to go through the motor to get it fully started. Each time the stalk is moved from Off, to an On position, the motor might move just a small bit. This changes the contact point between the brush and the commutator. Eventually, the movement is enough for the brush/commutator contact to improve, and the motor starts to run, appearing normal. This would also be consistent with your note about the engine rpm reacting slightly when the switch is turned to On.

I don't think turning the engine off is a factor. What happens if the key is turned to ON but the engine isn't started? The wipers normally would work then as well.

[subarufan]

plainOM- Sounds like a good possibility. I am surprised that it would become an issue since this component has not been used much on this car nor has this car been out in the elements very much during it's life.
No the engine does not need to be running for the issue to occur just did it so I could hear if a load occurred which it did.

Is it possible to get to those brushes and spray electric contact cleaner on them if it is infact just contamination??

Would hate to replace that part as it seems it comes with all the linkages and is pricey.

[tdelker]

Also, the nut could be loose on the wipers. This happened with my wife's OBXT 05. It was only one wiper through. Easy to check.

Tom

[plain OM]

I am surprised that it would become an issue since this component has not been used much on this car nor has this car been out in the elements very much during it's life. . . . .

Is it possible to get to those brushes and spray electric contact cleaner on them if it is infact just contamination??

Although it's rare, sometimes lack of use can lead to problems as well. Metal surfaces, such as the copper/brass commutator contacts, can oxidize. In addition, electrical contact lubricants, which are sometimes used to protect contact surfaces, can dry up, leaving a non-conductive coating.

I don't think the innards of the motor are accessible without taking it apart, and that would require removing the assembly to begin with. The cowl cover, the black plastic below the windshield, can be removed by taking off the wiper arms and then removing the various plastic pins that hold it in place. With the cover off, the motor and mechanism can be seen clearly and removed. At that point, it might be more apparent whether a spray cleaner could be used.

Perhaps try to make more frequent use of the wipers to see if the problem disappears, or at least seems to appear less often. If it doesn't improve, I'd start looking at replacement.

Hope this helps a bit. Let us know how it proceeds . . .

[subarufan]

So update, need more guidance....With the winter having come I have been using the wipers more and seemed to get better UNTIL today! Same thing as before moved the stalked to LO and no action then moved to HIGH no action then OFF and back to HIGH no action but left it on HIGH and in 20 seconds the wipers started going again. Moved back to LO for the trip to work and after work wipers worked on LO and switched to HIGH and they slowed down slower than LO.

Sounds like an electrical problem in the motor correct??

So A1Cardone has reman'd motors without the assembly P/N 43-4520. But when you look at the Factory Service Manual and Dealer parts list it shows the entire motor/assembly needs to be replaced. So which one is correct? Of course the pricing is significantly different.

[plain OM]

Before changing parts, seeing as you would have to gain access to the motor and the mechanism under the cowl cover in any event, it might be worthwhile making some measurements at the motor connector to see if the voltage is, in fact, getting there and correct. Your earlier description of the engine slowing slightly seems to suggest this; that the motor is drawing current, but not turning. However, if the voltage getting to the motor is low, the same could happen.

I'm attaching the wiring diagram I found for the front wiper. There's a five-terminal connector, B8, at the motor, where it should be possible to measure the voltage if it can be accessed. Terminal 2 is ground. Terminals 1 and 4 are the two run speed connections.

Alternatively, if the motor is removed, 12 V power could be applied to terminals 1 (negative) and either 1 or 4, and see if the motor will run.

I'd want to see if the motor can be conclusively found faulty, especially if a replacement is expensive. There's a possibility that the switch and/or the intermittent controller has a defect -- bad contacts or component.

I've only seen references to the complete assembly. It might be possible to separate the motor, but that might depend on how it's attached to the mechanism. Bolted could be fine, but riveted or spot welded could be more challenging.

[wilsonhp]

Is all of the mechanical stuff lubed and free to move?

[subarufan]

Originally Posted by wilsonhp

Is all of the mechanical stuff lubed and free to move?

Yes all the moving parts of the assembly have been siliconed and checked for any debris in and around the motor and arms.

[subarufan]

Originally Posted by plain OM

I'm attaching the wiring diagram I found for the front wiper. There's a five-terminal connector, B8, at the motor, where it should be possible to measure the voltage if it can be accessed. Terminal 2 is ground. Terminals 1 and 4 are the two run speed connections.

Alternatively, if the motor is removed, 12 V power could be applied to terminals 1 (negative) and either 1 or 4, and see if the motor will run.
There's a possibility that the switch and/or the intermittent controller has a defect -- bad contacts or component.

I've only seen references to the complete assembly. It might be possible to separate the motor, but that might depend on how it's attached to the mechanism. Bolted could be fine, but riveted or spot welded could be more challenging.

I checked the voltage at the harness and get the 12V and all seems to be correct. I dont have a way of applying voltage to the motor on a bench to see if both speeds work. I do know that HIGH speed does not work at all now but LOW and INT. do work fine.

From the looks of the parts break down the motor is attached to the assembly with a bolt/nut so I would think just a motor replacement is possible only thing is the nut is underneath the entire assembly so the entire assembly still needs to be removed from the vehicle so you can R/R the motor itself. It looks like the culprit is the circuit board on the motor which of course is not possible to buy standalone. Funny because its the same part as the recall on the 2010/2011 Subarus.