I bought my 98 F150 a few months ago. Shortly after getting it home, I noticed the heater core had been bypassed. I'm sure this was done by the previous owner to avoid a costly/difficult repair. My problem is, even though the heater core is bypassed, I am still getting water in the passenger side floor board. The rear glass was recently resealed. The water appears to be coming from the heater box, out of the floor vents. Any ideas on where to look while I'm replacing the heater core? I only want to remove the dash once!