Water leaks under the dash

[JohnBuongiorno]

Hello,I'm having the same issue on my 2014 however I'm not seeing any water stains on my headliner. Wouldn't there be evidence of a leak on the headliner if it were leaking through the shark fin antenna? Hopefully you see this as I just noticed your post was from 2019. Thank u

[Coolhand1958]

Hi, my wife had a 2016 Chev 1500 with similar issue. Found the following 3 items wrong.

 

1. Rear 3rd brake light leaking, would run over headliner and drip down channel on driver side then under dash and on the floor.  Pulled mats back and used fan to dry.  Sealed 3rd brake light with clear marine goop after cleaning well.

 

2. Found sunroof causing a leak, similar leak area as above.  Tested all channels with small cup of water, Driver side front not draining. Tryed using a compressor to blow it out. No Go. Used my electrical snake, cut of the end and pushed into channel carefully as it is a rubber tube. Found a live oak nut had wedged in tube.  I was able to poke nut with snake and pull out.

 

3. Found the Sirius / WiFi antenna leaking, had the rear vent [stupid design, must have been an engineering intern]  Pulled antenna and sealed with marine goop.  A bit of PITA to drop headliner to loosen nut on antenna.

 

Had to pull carpet up and dry with fan each time.

 

After 2 months she decided to trade truck..