Could the windshield replacement have been done incorrectly to cause water to enter through the firewall?
There was no leak the day before replacement, and now leaks after car wash.
The shop says there is debris blocking “ducts” and I need to go to the dealer for the cure. They stuck a garden hose down into the cowl and ran the water full blast to prove their point.
This seems nonsensical. The cover is screened to keep out leaves etc. and none are visible.
How did these alleged techs mess this up?
I can’t see your car, but it certainly is not uncommon for a car to have blocked drains from that area in front of the windscreen. It usually is not difficult to get to so you may well be able to clean it out yourself. If you can find the drain, use some string trimmer line or compressed air to open up the drain. Don’t over do it or you may damage the drain.
[b] The cover is screened to keep out leaves etc. and none are visible. [/b] The cover and screen just keeps the big stuff out. The finer stuff is the problem.
Having said that I don't know if they made an error with the window, but my money would be a blocked drain unrelated to the window.“How did these alleged techs mess this up?”
When they were cleaning up the windshield frame, they allowed old sealant to drop into the cowl ducts and plug them up…Or they were very near plugged up anyway…The plastic debris screen covering the cowl vent opening should not be THAT hard to remove…
The plastic grates help keep big leaves out, but debris and dirt still gets in there. If you park under trees frequently pollen and junk is smaller and can block the drain tubes. Some have success cleaning the tubes with compressed air. Sometimes you have to run a thin wire down the tube a la “roto rotor” style.
It is also possible to get a leak with a windshield replacement. I’ve got a crack in my Honda Civic windshield that has been there for years now. I don’t get it replaced for just this reason, no leak now so why chance it. Most replacement jobs go fine, but some do leak.
I do not know how your truck is designed but on some vehicles the cover for the cabin air filter can get knocked about or crack from age and therefore water leaks into the passenger compartment.
The probability of a leak starting right after the new windshield is very slight.
The water flows at a huge volume through the cowl and to the ground with the hose inserted inside the cowl (cover removed) before dripping inside the cabin from the heater.
Perhaps you are thinking of the condensate drain hose from the AC. This line could become blocked and drip inside when the AC is on.
The problem is outside water, rain or carwash getting inside.