Seeing that this is your first post, welcome to iRV2.com.
We're glad to have you join us.
Looking at your profile, you show a 1998 36' Fleetwood Prowler. I'm assuming that's the RV with the crack in the exterior wall.
I really don't have enough information from your post to comment. There are any number of reasons a crack might develop in an exterior fiberglass wall. It might initiate from a stress concentration point at the corner of a window - is this the case with your crack "near the window"? Do you see any signs of delamination - bubbling in the exterior skin, etc.? Could water have gotten into the exterior wall around the window due to deteriorated sealing material? How long is the crack? Is this the only crack you've found on the exterior? Is your exterior fiberglass filon or gelcoat?
The more information you can provide (photos are especially helpful), the more accurate will be the responses.
I'll link this down into the Fleetwood Owner's Forum as well to see if other Fleetwood owners might be able to help.
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