Winnie's are famous for front window leaks. Before my windows cracked and were replaced, with the frame ground down and coated with anti-rust, I installed 4" wide vinyl tape around the windows over the rubbers, 2" on the glass (doesn't block vision much at all). Then vinyl stick-on gutters over the windows, fronts & driver's window. Here's my blog post about all I did, note that after the new windows were installed, I eliminated the vinyl tape around the windows, but I kept the gutters in place.
Weather Proofing...
Then bathroom silicone around three sides of each of the front running lights (2 of them were leaking inside, dripping on the dash). Then 4" Eterabond tape on the front and rear end caps seams. A friend had her's leak into the overhead cabinet over the door and badly stain the ceiling, then down into the step well. Than I put 2" Eternabond tape along each side seam of the entire RV. Not sure if your roof would accommodate the tape, but perhaps?
My dash AC/Heating works fine and any condensation drips outside under the passenger side front. The box where the drain hose is, is on the outside of the firewall under that front hatch your rig seems to have. Wouldn't hurt to run a wire up in there to make sure it's not blocked by a bug of some kind.
For the
heater core, you'd smell anti-freeze if it were leaking unless the AF has been replaced with just water. But you can test the core for a leak by pulling the two hoses that go to it and inserting a coupler between them or just clamping one shut with a flat mouth vice grip.
Step by step, you'll find the leaks, but they can be legion.
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Linear Mode
