Windshield wipers are staging a protest when it rains

I have a 2011 Ford Fusion SE, and a couple weeks ago the wipers started behaving erratically. They always work, but they’ll pause for a beat or two for no reason, or they’ll work at a slower speed than the one I’ve set them at. They don’t have any issues parking, and they have the range of motion they’re supposed to have. They only do this when it rains. They do not act weirdly if I’m just cleaning my windshield, or if there’s a mist being thrown up from the road but no actual precipitation. A hard rain seems to have more effect than a slight rain (though this could just be skewed observation from using the wipers more during those times).

It seems to me that I should start by seeing if there’s somewhere in the electrical components where water is getting in. I’ve done a little DIY car repair, but not much so I’d appreciate any ideas/advice!

There has to be a short developing when moisture enters where it should not. I would start with an auto electric shop that knows what it’s doing and explain you are getting water penetration somewhere.

If you are due for new wiper blades, you might put some Vaseline or some other grease on the blades and run the wipers. If the wipers behave. normally, then moisture is getting into a connection. If the wipers act up, then I suspect the motor may be causing the problem. Be sure to clean the windshield with isopropyl alcohol and install new blades after this experiment.

I vote with Doc.
The water on the windshield may have nothing to do with it.
But, the moisture in the AIR . . the relative humidity . . may be the culprit in either the switch, motor, or any of the plugs in the system.
now . . how to prove where ?
Also the road spray up from the tires into the fender wells might br getting in to something.

I have the same problem with my 2011 MKZ (Fusion based). It doesn’t require rain, same thing happens when I use the windshield washer. I haven’t found a solution. I plan on searching the Fusion forums, see what I find out.

If you are due for new wiper blades, you might put some Vaseline or some other grease on the blades and run the wipers.

Personal experience? Contaminating the windshield with grease seems to be a bad idea.

Your car may have the rain sensing wiper system. The wipers will pause if no moisture is detected by the rain sensor.

Not mine, don’t think the Fusion had a rain sensing system, either yes, there was a rain sensing option. Problems with that are common when the windshield gets replaced. The erratic behavior happened for a while (like continuous wiping when set on intermittent, odd parking, two wipes instead of one on intermittent, etc.), then went away for months. Now it’s coming back.

I found this on the Fusion forum, along with comments that the multi-function switch is often the culprit:

"Do the wipers operate normally on the low/high settings? If so, these are the components to be tested, per the SM:

:black_medium_small_square:Wiring, terminals or connectors
:black_medium_small_square:Multifunction switch
:black_medium_small_square:Wiper/washer module"

A replacement switch is $70 at Rockauto.

No rain sensor on the windshield? I would expect rain sensing wipers to be a common feature on a Lincoln, this has been offered for more than ten years by other manufactures.

On the Ford vehicles with rain sensing wipers there is no intermittent setting on the control, the incremented lines are are for the sensitivity setting. When using this setting the wipers actuate when needed.

If the car has rain sensing wipers the switch can be left in one of the auto positions with the lines, the wipers won’t operate until the glass is wet, some owners leave the switch in that position.

Rain sensing is an option I didn’t get. Pretty sure it was part of a ‘pack’ with the sunroof, which eliminated it for me.