Front wipers randomly turn on

This could be a couple of issues so the way we need to figure this out is to start checking power through the wiper system when the wipers are on, and the switch is off.

Basically, we need to find out where the power is coming from. This is most likely a short or connection issue but normally a loose connection normally causes them to cut off.

https://www.2carpros.com/articles/how-to-check-wiring

On newer vehicles when the module loses connection it will default the wipers on as a safety measure. This vehicle does not have this.

So I suspect this issue is there is a wire that is rubbed through and when you hit the right bump it grounds out and turns the wipers on.

I am attaching the wiring diagram below but let's start at the motor and work backwards when the wipers are on to find where we do not have power.

Let me know if you have questions on this but this could be a relay issue as well so let's start with this and go from there.

Thanks

You mean the program in the wiper motor that if you turn the switch off in any position other than 0 (parked position) that the wipers will finish that swipe and then stop in the parked position?

It could be the issue, or it could be the wiper motor itself. Either way, when this is happening that will show up because we will have voltage on the dark green/white wire when they are running, and the switch is off. This is the park control wire. Basically, when the motor is commanded off by the switch (turned off) then the BCM will keep the motor running until it reaches that parked position and then cuts it off.

No matter what, we need to test the voltage on these wires when the motor is running, and the switch is off to see where the voltage is coming from.

That is interesting and not expected.

So, the BCM controls all wiper functions and the only way you are going to get voltage on both of the motor wires is if the BCM Is grounding the relays.

Do you think you can get a video of how you are testing the park circuit and it cuts the wipers off?

That makes me think we have a BCM issue because that wire is normally grounded and when you are probing it, I suspect you are just grounding the circuit and that causes the wiper motor to park the wipers.

That is great. Okay, yes. I suspect the motor would be the issue.

Basically, the park switch is inside the motor assembly. The fact that you recently replaced the BCM pretty much leaves the motor. The only other thing it could be is a sticking relay. However, I thought you said you already replaced that.

Good plan. The only reason I think the relay is the issue is because you had power on both sides of the motor which is fed directly from the relay. So, if the relay is sticking on then that would explain it as well.

However, I am with you that I suspect the motor is more likely.

That is great. Thanks for updating us and letting us know that it was a relay issue.

Glad the wiper motor didn't need replaced either and I am glad I was wrong.

Thanks for using 2CarPros.