Hello, I'm new and of course hoping for some help. This is becoming a desperate situation. I have a water leak into my 2012 E450, this is a Forest River motorhome. I called the Ford Big Rig service help line, but they didn't really help much. I've scoured the internet for causes and methods to determine where the leak is coming from, and so far nothing. It's dripping in the driver side, near and into the fuse box, onto the floorboard, it runs down and pools near the foot rest area. It's a water leak, as it happens when it rains, or when I wash it.

I removed the windshield cowling to get a better look at it, the windshield seal was rotten, so I replaced it. That didn't stop the leak. My next thought was where the bundle of wires go through the fire wall, I placed some aluminum tape above, that seemed to help, but then it started leaking again. I sprayed water from the hose, starting low, watching for a leak, then spraying higher, and wider, I'm not getting a solid result. It rained last night, and there's water today.

Are there some drain plugs in the wiper channel area that could be rusted up? From inside, I can't really see where it's entering, there's a lot of wires, duct work and other stuff blocking the view. This is particularly concerning with it leaking into the fuse box, I've been using a shop vac to suck any moisture out. I'm not sure how to approach it at this point, and am hoping someone has a suggestion on where the most likely leak could be coming from.

For some reason I'm not able to get a picture to post.

 

Remove the dash so you can see better. My alldata covers up to 2007 for your reference.
Never rule out it is leaking from the roof thru a-pillar, so check Headliner-Removal.pdf too.

 

Thank you for the reply and info. I wasn't thinking the dash board would need to be removed, but that makes a whole lot of sense as it would provide the best view. Briefly looking over the documents you provided is kind of overwhelming at this point, I've never removed a dash. I need to keep studying the process, build up to it, and plan ahead. I'm kind of leaning toward the windshield being the source of the leak, but I've gotta know for sure.

I also had a leak between the cab and bunk, being a class C, I literally just finished that. I was in the process of soundproofing the cab, when I pulled up the floor mat and it was soaked underneath. I had just finished washing it. That was a chore, had to build a scaffold to work on, then come up with extension tubes to reach the caulking between the cab and bunk. While I had the scaffolding there, I replaced all the overhead lights. And now this.... I just want to work on mods, not repairs. LOL

Right now I just want to say a quick thanks.

 

Yes remove the dashboard and headliner and a-pillar then you have a clear view. You can also pour a liter of unsweetened coffee or tea, you might not see the darker color water leaking till tomorrow or so, that means you have water buildup somewhere when you see clear water still. Try not to use ice or hot water for testing, you may crack the windshield when doing so.

 

You can obtain a tube of windshield sealer and do all around the windshield. Then you will be sure it is not the source.

If it still leaks, one of the little tricks is to spray some talcum powder where you can see and that might help reveal the source.

If your truck has cab lights on the front of the roof, make sure that is not one of the places water can get in.
Anything that is leaking now has to be below a certain point because you covered all the upper parts, I hope.

Taking a dash covering off can get a little involved and I would try to cover the easier parts first.
If you decide to remove the dash covering, lay out what you remove in an order so when it comes to reinstall them, you just reinstall in the reverse order.

 

I have a high level of confidence I've found my leak, the lower corner of the driver side windshield. I have an outside windshield privacy cover that goes over the windshield, and around both door windows. I put it on, making sure it covers only the windshield, and have been spraying it with water off and on for the past 12 hours. I've checked it several times, and so far it's not wet inside. By covering only the windshield, this allows water to run down the cowling and anywhere else water may intrude, and so far that area has held up.

One more thing I'm sure I need to do, remove the fuse box (BCM) and check it for water damage or corrosion. I have a feeling this leak has been going on longer than I realize.

 

Resolved.... I jumped the gun on the windshield being the leak. I purchased an endoscope camera, a cheap one off of amazon that hooks up to my iphone, and using that I was able to track the water to a fairly specific area. With the windshield test, I wasn't running the water hard enough. The leak was under the cowling, in the channel where the windshield wipers are, in the back corner near the driver door. I ran water directly into that spot, and it started leaking right away. I caulked it, and have been running lots of water directly into it, and off the windshield, and no more leak.

That endoscope camera is great, it saved me from having to remove the dash, and I have it for future needs.

Thank you for the suggestions.

 

Great idea, thank you for the update.