I've had my 2011 for 3 years. I've had to have 4 wiper motors installed. I just had to replace the smart junction box (took dealer 3 times to get it right) when I cranked it the other day the windshield wipers turned on with the car. The transmission is also slipping second gear (automatic). Has anyone else been going through wiper motors like this?

 

I ran across a thread on one of the Mustang sites a few years ago about the wiper motor issue. I cant completely remember all the details but it is an issue when the cowl drain plugs get stopped up and allow water to build up and run into the cabin filter then down over the SJB on the pass side kick panel. the issue with the wiper motor was also due to the stopped up plugs as the motor sits in the cowl channel (I think). I cant remember if it was the drain hole on the wiper motor itself, the orientation of the connector plug or the SJB in conjunction with one of the other I just mentioned. if your cabin air filter is plugged with leaves and such then the cowl channel will fill up and get around the wiper motor. I want to say it had something to do with the connector shorting out and melting kind of like the engine fuse box does under the cooling fan relays but im not 100% sure. should give you a few places to start looking and if you have stopped up cowl plugs or the 10 cowl trim clips leaking, a good time to fix those as well. good luck

 

FIXED!! (for my Mustang - Your mileage may vary)

My 2012 just experienced this wiper motor issue on Sunday evening - I pulled the wipers fuse (#45) out of the Smart Junction Box within 7 minutes of this issue starting once I pulled off the interstate. The service manual was almost useless, but the forums lead me to the clogged cowl drains problem. Tuesday I pulled the wiper transmission and motor assembly out of the cowl - had to use my battery terminal puller to remove the wiper arms.

With the motor/transmission out, I pulled off the circuit board cover from the motor, water drained onto my leg as it loosened.

I then took this circuit board cover outside, shook it to evacuate as much water as possible and let it bake in the Florida sunshine all afternoon while I attended to the clogged cowl drains. Both drains were plugged pretty good even though there were only a couple of leaves in the cowl area.

This morning I plugged the harness back into the reassembled motor and tested the operation. The motor no longer ran by itself, and it seemed to respond to every Multifunction Switch input, so I'm cautiously optimistic that things are back to normal. If there are other hiccups down the road, I'll update here.

 

What a coincidence...I'm currently in the middle of this exact issue with my car. It would seem the Ford engineers didn't truly believe in rainwater or related debris when they designed these.
The poor plug and circuit board looked like they'd been sitting underwater for days

QUESTION for those that have replaced the motor: are the bolt holes on the (new) motor really meant to be threaded by the installer via the self-tapping bolts that are on the vehicle?

I've now received two new Motorcraft motors without threads on those bolt holes, and a Ford parts person later confirmed this was "by design". Seems a bit crazy to me... I can find no evidence of this on the Internet. All the YouTube vids just show "bolting on the new motor"; they are clearly not putting enough muscle into it to be tapping those holes.

 

I figured I better check the condition of the cowl on our Solara that also sits under the huge oak tree in front of our house. Toyota thoughtfully left giant gaps at the left and right sides of the cowl cavity, leading to ZERO accumulation of debris/water/etc. I only had to vacuum up the acorns and caps off the cowl screen to get into the cavity. And this car being 8 years older than the Mustang, provided no hinderance to pulling the wiper arms off the splined shafts. I just unbolted the retaining nuts and the arms simply slipped off.