So over the past year, on my 2014 Pilot I have noticed that I will get an intermittent squeal noise from the engine bay during or after rain, or even right after driving through a big puddle of water on a dry day. Sometimes it seems like the alternator goes blink as well for just a second or two. I have checked all the splash shields and they are in place. What would cause this behavior to start up? I changed the water pump and serpentine belt two years ago, and alternator a year ago.

Tensioner?

What brand belt?

I think the belt is by Gates, replaced last year with the alternator. And the year before that we used an Aisin timing belt kit that did include the tensioner?

Your timing belt is not making noise. It's the accessory belt.

I'd inspect pullies for warpage and glazing.

I like Bando and continental belts.