Front wipers don’t work, rear does?

[Ronderwear]

I found this thread as I have the same issue on my 2015 Focus. Any conclusion? I'm automotive software developer so I'll fill on some blanks. The BCM is a computer that controls a bunch of stuff on the car. Including the keys and alarm. It controls the left wiper controller via a LIN bus wire that is physically attached to and activates the left motor. Another LIN wire is connected from there to the right motor. The power that is supplied to these motors is constant. The digital signal over the LIN wire tells them what to do.

In my case, the left motor/controller gets power and live data from the BCM. I used a signal analyzer to see the LIN bits. My guess is maybe the motor or it's controller are dead.

This all started when I disconnect two cable assemblies from the BCM in order to more easily access the cabin filter. In hindsight I should have disconnected the battery before.

I'll try a new wiper motor and see.

[Ronderwear]

Quick update: I got a "new" wiper motor. Had to go to Pick and Pull and yank one out of a wreak as AutoZone didn't even have one available to order.
Works now so I'm happy. $40 and not too much time. Would've probably spent more time at Ford with a $1000 bill.

So yes. Disconnecting an unrelated cable from the BCM killed the wiper motor (the controller part of it. I'm sure the motor itself is fine). Ford and Bosch should check themselves.
Takeaways are if the wire has power, ground and data: it's probably the motor assembly. You'll need some kind of very basic oscilloscope to see the LIN data but those are cheap.

[Aberk25]

I hope this thread is still alive enough to help me out. On my 2015 focus, the passenger side wiper stopped working but the drivers side and rear still work. I tried replacing the passenger side motor. wiper fuse. battery. Negative battery cable and current sensor. And last I tried the multifunction switch. The new switch made the front wiper run continuously and still did not make the passenger side work. Am I runderstanding it correctly from the last post that the switch sends a signal to the bcm and then to the drivers side wiper motor which sends a signal to the passenger side? So is it possible the drivers side could still work but not be sending a signal to the passenger side?

[unofix]

1 hour ago, Aberk25 said:

I tried replacing the passenger side motor. Wiper fuse. Battery. Negative battery cable and current sensor. And last I tried the multifunction switch.

That's a lot of guessing !!!

I would recommend doing some logical fault finding with FORScan and a good multimeter. Start by checking to see if there are are Ford specific DTC's stored. Then a schematic wiring diagram of the wiper circuit will be needed and you can do some checks on supplies and interconnecting wires.

Is your car RHD or LHD ?

If the wipers become out of sync with each other, then one of them will stop working so that it doesn't crash in to the other wiper. The motors of both wipers have to be re-synchronised. It may be possible to do that using FORScan.

[Aberk25]

My car is LHD. I can confirm that there is power going to the passenger side motor, I was cleaning the contacts with a wire brush and got a spark...whoops... Any programming is way over my head unfortunately. If i were to try to replace the drivers side motor would I have to program it for it to work or would it be plug and play? I have seen in other threads that the problem ended up being the actual wiring between the two motors. I am running out of ideas that are feasible for me to try before taking it to a dealership and dropping what i can only assume to be an absurd amount of money to have a wiper fixed... 

[unofix]

Hello Alec, unless you are confident in using a laptop with FORScan software then it is unlikely that you will sort this problem. The two wipers have to be synchronised other wise they would keep hitting each other. Changing motors will not sort the problem.

[Dan62]

It only leaves the drivers side motor to change, its got to be a cheaper option before involving a dealer?
The diagram is accurate apart from the wiring colour for the motor power which yours will probably be yellow/red instead of Brown/Red.
Also the left/right motor could be reversed as the diagram is for RHD

The LIN Bus response from the drivers side motor could be the issue and the motor is running in limp home mode.

That's my guess.

wipers.pdf

[Joeywv81]

Ok I hope I may get some help. 2014 Ford focus SE the wipers don't work at all. I have replaced the fuse under the hood and replaced the stick in the car. I have checked the motors which is where it gets weird . The drivers side motor is saying g it has 15.7 volts with the key in auxiliary position. The passenger motor is saying 0 volts I have been scratching my head on this situation along with other friends that are car people. I bought 2 motors from a junkyard neither of them are working either. I've been reading that the BCM could be the issue. How can we afford something like this from only the dealership there gonna try and charge 1000s of dollars that I can not afford. Any solutions would be helpful.

[Rowan112]

2 hours ago, Joeywv81 said:

Ok I hope I may get some help. 2014 Ford focus SE the wipers don't work at all. I have replaced the fuse under the hood and replaced the stick in the car. I have checked the motors which is where it gets weird . The drivers side motor is saying g it has 15.7 volts with the key in auxiliary position. The passenger motor is saying 0 volts I have been scratching my head on this situation along with other friends that are car people. I bought 2 motors from a junkyard neither of them are working either. I've been reading that the BCM could be the issue. How can we afford something like this from only the dealership there gonna try and charge 1000s of dollars that I can not afford. Any solutions would be helpful.

have you checked fuse 42 in the main fuse box in the engine bay?

Have you also checked F85 as that's the fuse to the rear wiper relay?

F33 in the boot is also rear wiper too??