I just replaced the passenger floor pan in my trans am, I found that water has been coming in through the ecm wiring port behind the passenger side kick panel. Should I just use seam seal to seal this or is there a better alternative?

 

Mine leaked there too. A dealer had smeared a lot of silicone over the area, but missed the leak.

To supplement the factory foam gasket, I rolled a thin bead of dum-dum out by hand, and applied it on top of the foam gasket. Spread out real nice when the pass-through was reinstalled in the cowl side panel.

Here's the product.





And here's a thin bead of it rolled out, and applied to the edge of a speaker for the dash, to prevent rattles.