Water leak at passenger side A pillar

Hello everyone,
I am a new member here and of course I have questions! Last week I purchased a new to me 2018 Tacoma SR. It had a bit of a musty smell to it when I got it. Yesterday it sat in the rain in the driveway and when I got in it I noticed some dripping water coming from the top rear edge of the passenger side A pillar. I have read about the leak issues with the rear center brake light on the cab but I don’t think this is that problem. I will try to attach a photo of the wet area.
The cab is an access cab with no sunroof. I suspect the leak location is associated with the windshield seal at the top of the passenger side. Any thoughts about how to diagnose? I may apply soapy water to the exterior in that area and then blow compressed air towards it from the inside.

 

With no sunroof to blame it on, I would suspect one of the roof rack channel mounting holes. I too doubt that a leaking 3rd brake light could make it that far forward.

 

Does it have a roof rack?

 

With no Sunroof there can't be many culprits. I had same issue on a F150 yeas ago and it was the GPS Antenna on the roof

 

dry it. then test small areas around the glass and door seems with water hose on low pressure so you can isolate the area you are testing. then move to top roof channel. working bottom to top with testing

 

does it look like new non OEM front windshield? should have Toyota written on it down at the bottom. they usually put in new windshields as part of the used slick Rick Larry used car sales process.

 

Access cab has roof rack mounting holes?

 

Sorry, did not catch the AC part. Who drives those things?

 

The previous owner either replaced the windshield or drilled holes for a roof rack. Pull up on the drain channel weatherstripping and see if there are holes.

Does your center brake light look OEM? The access cab brake light has an old-school red lens with three filament bulbs inside. If the previous owner replaced the whole unit with an LED light, that could cause leaks.

Leak from the sharkfin antenna is also possible but not systemically reported. Could've been accidental damage (e.g. hitting an overhead item in a low parking garage).

 

Thanks for the quick replies folks. I will check into what has already been suggested and report back.
Thanks for the replies so far.