I was wanting to know the function of the stock lights on the mirrors. I have a 2016 XLT with basic mirrors. Do these lights function at any time? All I can see them do is flash when unlocking the doors....or it might be when locking. Anyway I was wanting them to function as parking/running lights. I do have the DRL’s off if that makes a difference......never messed with them. Thanks for any info you can offer.

 

They are puddle lights. They light up when you lock / unlock / open either door. They are nice in the dark night.
Or are you talking about the side lights that are for working? They only work in park condition (thank God), or idiots would be driving around blinding people.

 

Not sure if the XLT allows it, but there is a wiring harness you can buy (after market) and splice in so the mirror lights function as running light.
Otherwise, they are there as turn indicators that we as the drivers don't get to see.

There are a few YouTube videos of owners doing the install.
Check them out. Maybe search something like "f150 mirror parking lights'

 

Before this gets anymore confusing for you, which lights are you referencing?

There is/could be turn signals, puddle lights, and spot lights; three separate lights with three different functions.

 

I’m sorry for the confusion. They are blinker lights as I just confirmed do work....I could have sworn they didn’t work when I tried before. I was thinking of having them work as running lights also, I will look on YouTube for a video. Thank you for the replies.

 

Seems clear cut the OP is talking about the turn signals in the mirror. No other lights on the mirrors flash.

 

I think you are looking for this setup?

 

That Boost Auto Parts unit is what I have on my '20. Wish they supplied printed instructions, but I managed anyway. The attraction I had with them, is that the turns on the mirrors blink synchronized with the turns in front and rear.
There is another unit out there, "Blinker Genie", that does the same, and a bunch cheaper. Thing with this one, your mirror turns blink opposite of the front/rear. I had this one on my '17.
Choice is yours, I picked the Boost part because of the synchronization, and paid a butt ton more, just me I guess.