Windshield wipers only work on high setting.

[TheRaven]

I searched all over the net and I could not find a Ford with a problem like i'm having.  Lots of wiper issues but nothing that quite matches what happened to my car.

So here goes - Monday morning, driving to work, had the wipers on low setting.  About halfway through my drive I noticed the wipers were acting weird - on the return side of each swipe it looked like they were struggling to get down.  They swept up fine but kinda "ran out of juice" on the down swipe.  I turned them off and back on, same.  Tried intermittent, same.  Tried high speed, and that worked perfectly.  My immediate thought was maybe the alternator was dying but then the high setting should be affected too, but it wasn't.  To finish the story - over a two-day period, they just kept getting worse until they completely stopped working on intermittent/low.  High speed still works perfectly and reliably every time, but now they will not move at all on low/intermittent. 

This is apparently unique because of the way they died a "slow death".  Every instance I see online is either the switch, relay, or motors.  But it seems like my situation rules them all out:

- Can't be the switch because they would have just stopped working, or stopped working reliably.  The switch can't make them slowly die. 

- Can't be the relay for the same reason.  When a relay quits things just stop.  

- Can't be the motors because they both died in the exact same manner and rate.  No way two motors will go that way.

Is my logic sound?  And if so, is there a wiper module that could be responsible?  A speed controller perhaps?

[bbf2530]

1 hour ago, TheRaven said:

I searched all over the net and I could not find a Ford with a problem like i'm having.  Lots of wiper issues but nothing that quite matches what happened to my car.

So here goes - Monday morning, driving to work, had the wipers on low setting.  About halfway through my drive I noticed the wipers were acting weird - on the return side of each swipe it looked like they were struggling to get down.  They swept up fine but kinda "ran out of juice" on the down swipe.  I turned them off and back on, same.  Tried intermittent, same.  Tried high speed, and that worked perfectly.  My immediate thought was maybe the alternator was dying but then the high setting should be affected too, but it wasn't.  To finish the story - over a two-day period, they just kept getting worse until they completely stopped working on intermittent/low.  High speed still works perfectly and reliably every time, but now they will not move at all on low/intermittent. 

This is apparently unique because of the way they died a "slow death".  Every instance I see online is either the switch, relay, or motors.  But it seems like my situation rules them all out:

- Can't be the switch because they would have just stopped working, or stopped working reliably.  The switch can't make them slowly die. 

- Can't be the relay for the same reason.  When a relay quits things just stop.  

- Can't be the motors because they both died in the exact same manner and rate.  No way two motors will go that way.

Is my logic sound?  And if so, is there a wiper module that could be responsible?  A speed controller perhaps?

Hi TheRaven. I won't be much help here. However, I can add my thoughtts/opijnions. First, I'm not so sure you can rule out a failing switch or relay.  Second, as far as I know, there is one wiper motor and it drives both wiper arms. If one of those three can possibly be ruled out, I would guess the motor is not the issue, since it is currently working when set to high (and I could very well be incorrect).

Hopefully one of our more Lincoln/Ford tech knowledgeable members will weigh in soon to help you.

Keep us updated and good luck.

Edited September 13, 2018 by bbf2530

[TheRaven]

54 minutes ago, bbf2530 said:

Hi TheRaven. I won't be much help here. However, I can add my thoughtts/opijnions. First, I'm not so sure you can rule out a failing switch or relay.  Second, as far as I know, there is one wiper motor and it drives both wiper arms. If one of those three can possibly be ruled out, I would guess the motor is not the issue, since it is currently working when set to high (and I could very well be incorrect).

Hopefully one of our more Lincoln/Ford tech knowledgeable members will weigh in soon to help you.

Keep us updated and good luck.

Why would you say I can't rule out the switch or relay?

Also, Fusions have two wiper motors so my assumption would be that the MKZ is the same.  Wouldn't blow my mind to find out that i'm wrong about that though.

But it is also my thinking that the motors must be ok because the high setting works perfectly every time.

[bbf2530]

1 hour ago, TheRaven said:

Why would you say I can't rule out the switch or relay?

Also, Fusions have two wiper motors so my assumption would be that the MKZ is the same.  Wouldn't blow my mind to find out that i'm wrong about that though.

But it is also my thinking that the motors must be ok because the high setting works perfectly every time.

Hi TheRaven.  As far as I know, the 2013 MKZ has one wiper motor. When I access diagrams, I see one motor driving connections to both arms. See this exploded diagram: https://www.bluespringsfordparts.com/auto-parts/2013/lincoln/mkz/base-trim/2-0l-l4-gas-engine/electrical-cat/wipers-scat

I agree that it is probably not the motor.  Sorry if that was not clear in my first post. But as I said, I could also be wrong.

I feel you shouldn't rule out a failed/failing switch or relay because I have had experience with switches and relays failing over time.  But again, I am not an expert in the field and would defer to one of our more tech savvy club members. Hopefully they will jump in soon.

Keep us updated and good luck.

 

 

[TheRaven]

22 minutes ago, bbf2530 said:

Hi TheRaven.  As far as I know, the 2013 MKZ has one wiper motor. When I access diagrams, I see one motor driving connections to both arms. See this exploded diagram: https://www.bluespringsfordparts.com/auto-parts/2013/lincoln/mkz/base-trim/2-0l-l4-gas-engine/electrical-cat/wipers-scat

I agree that it is probably not the motor.  Sorry if that was not clear in my first post. But as I said, I could also be wrong.

I feel you shouldn't rule out a failed/failing switch or relay because I have had experience with switches and relays failing over time.  But again, I am not an expert in the field and would defer to one of our more tech savvy club members. Hopefully they will jump in soon.

Keep us updated and good luck.

 

 

Yeah I am ruling out the switch based on my knowledge of switches and the fact that a bad switch cannot account for a very slow failing of a motor on one particular speed but not on another.  If it had just abruptly stopped working then I would actually bet on it being the switch.  Now that is unless someone comes along with knowledge that the "switch" is not really a switch at all but something that can actually regulate the voltage received by the motor.  That would be a different story (and a really dumb design).

Now if there's a single motor then I cannot rule it out.  Electric motors generally have starting solenoids and/or caps and in a two-speed situation may have multiple sets for the different speeds.  It would be a poor application of this design to use it on a modern car since automakers tend to use external modules for this sort of thing anymore.  Nonetheless, it's possible that a dead solenoid or cap could cause one speed of the motor to "go out".

We'll see if anyone here knows more than we do about this.  I'm betting there has to be a "wiper module" somewhere, and it probably got water in it somehow.

[drolds1]

4 hours ago, TheRaven said:

Why would you say I can't rule out the switch or relay?

Also, Fusions have two wiper motors so my assumption would be that the MKZ is the same.  Wouldn't blow my mind to find out that i'm wrong about that though.

But it is also my thinking that the motors must be ok because the high setting works perfectly every time.

Fusions have two wiper motors, MKZs do not.  The Fusion uses opposing wiper arms while the MKZ does not.  The European Mondeo and the NA Fusion are basically the same car but since the Fusion is sold in UK countries it's more cost effective to equip the with opposing arms so that they don't have have build two different parallel arm systems to accommodate LH and RH drive countries.  The MKZ is not sold in Europe.  You'll notice the same thing on a Ford Escape, which is the Kuga in Europe as well as on the Focus.

Fusion wipers in action

MKZ

Possible sources:

Quote

• Fuse
• Wiring, terminals or connectors
• BJB (battery junction box)
• Windshield wiper motor
• SCCM (steering column control module)
• BCM (body control module)

You'd really need a Ford scan tool to diagnose this.  IDK if ForScan could do it.

 

Edited September 13, 2018 by drolds1

[TheRaven]

3 hours ago, drolds1 said:

Fusions have two wiper motors, MKZs do not.  The Fusion uses opposing wiper arms while the MKZ does not.  The European Mondeo and the NA Fusion are basically the same car but since the Fusion is sold in UK countries it's more cost effective to equip the with opposing arms so that they don't have have build two different parallel arm systems to accommodate LH and RH drive countries.  The MKZ is not sold in Europe.  You'll notice the same thing on a Ford Escape, which is the Kuga in Europe as well as on the Focus.

Fusion wipers in action

MKZ

Possible sources:

You'd really need a Ford scan tool to diagnose this.  IDK if ForScan could do it.

 

What if I pull the motor and test at the connector?  I should be able to meter two different voltage levels depending on the position of the wiper switch.  If it's not the motor, theoretically I should see no voltage on the low setting and some voltage on the high setting...if I see voltage on both settings then the motor is the problem.  Right?

[drolds1]

Sounds logical but my knowledge of testing electrical systems is limited.  Maybe someone else will weigh in.

[TheRaven]

Wow this forum is a ghost town.  

Well i'll do my best to contribute at least...

Disassembled the wiper system this weekend so I could test the motor.  Test was inconclusive, voltages at motor make no sense.  It doesn't appear to be wired the way every other wiper motor ever has always been wired...no surprise.  I then decided I would simply buy a new motor and just plug it in for testing, see if the different speeds work but OF COURSE no one has any in stock.  So I put everything back together because I need to drive it this week and guess what?!  It all works perfectly now.  High, low, int, and auto...all working as they should.

Neat.

So, assuming it STAYS working, my guess is connectors.  In addition to unplugging the motor, I also had to unplug the two large bus connectors at the engine bay fuse block in order to get to the fuses UNDERNEATH the fuse block (awesome idea Ford).  So perhaps re-seating all of those connectors alleviated the issue.  This week promises to test the wipers hard so i'll report back in a few days.

[TheRaven]

UPDATE:  Problem still exists.  So really, it only gets weirder.  I've discovered that when I disconnect those two connectors at the underhood fuse box, leave them out for like 10 minutes, then reconnect them, the wipers work perfectly, but if I leave them running, they slowly die over a period of about 30 minutes.  Then, the low speed is completely gone.  No low, int, or park functions...only high works.  I can repeat this cycle ad nauseum.  WTF?!

[bbf2530]

2 hours ago, TheRaven said:

UPDATE:  Problem still exists.  So really, it only gets weirder.  I've discovered that when I disconnect those two connectors at the underhood fuse box, leave them out for like 10 minutes, then reconnect them, the wipers work perfectly, but if I leave them running, they slowly die over a period of about 30 minutes.  Then, the low speed is completely gone.  No low, int, or park functions...only high works.  I can repeat this cycle ad nauseum.  WTF?!

Hi TheRaven.  It seems you need more technical assistance than most of us are able to provide.  Perhaps a more tech knowledgeable member (such as eGuru) will see this and jump in with ideas. If not, a trip to your Dealers Service Department or another shop may be necessary.

Keep us updated and good luck.

[DENALIAKITAS]

Anyone ever figure out what resolved this issue? Mine is doing same thing now. All fuses are good.