Model 30B with a wet basement compartment - Help

[BubbaJePH]

I have a new 2007, purchased 5/2009, First owner Itasca SunStar 30B. I've seen one other of the same model that has the same problem as I do. My basement compartment under the shower is damp. The ceiling and walls in the compartment are damp. I've winterized the model. I blew out the water lines with less than 40 PSI. Then I used the pink antifreeze to charge all the lines with the water heater in bypass. I also poured some antifreeze down the P Traps. The moisture in the basement compartment is not antifreeze or anything I've done. I took the panel off to look under the shower. I also took off the panel that is the back side to the shower wall. All fittings are tight. No sign of water leaks. The top of the gray tank is visible. It is dry. I'm wondering.... If there was moisture inside the gray tank and this side of the RV is facing the sun all day. Wonder about temperature changes causing condensation to form on the outer surface of the gray tank and it is dripping onto the outer ceiling of the basement compartment. I cannot get my hand between the gray tank and the compartment to feel for moisture between the two

Does anyone else with a Winnebago / Itasca model 30 B have / have this problem?
What did you find out to be the problem? Thanks!

Jeff

[Easyrider]

We don't have the same model as you but you might be onto something with the condensation. We had some condinsation forming in the area above the windshield that was so bad at times we originally thought we had a leak in the windshield seals. Then I noticed we didn't have any leaks when driving in a hard rain and had water dripping like crazy when we hadn't had rain in weeks. Good luck getting it figured out.

[BubbaJePH]

My friend that has the other 2007 Sunstar 30B was told he would need to cut a ventilation hole in the wall of the basement compartment to allow air in and hopefully solve the moisture problem. I'm still under warranty and I do not want to screw anything up there.

[ChasA]

Bubba,
Did this occur after a rain? If so, the problem could be your rubber-ducky antenna for the outside radio isn't scewed all the way into its base. I had that problem on my 29R. The water was going into the cup base of the antenna and down the coaxial cable, into a big bundle of wires whose low point was into the compartment and dripping in there. I found the antenna barely screwed into the base. I tightened it and no more leaks. I hope your fix is as simple of mine was.
Chas

[BubbaJePH]

It happens different times. Warm to cool days. Rain or not. My radio antenna is on the front of the motorhome. The basement compartment is just behind the rear wheel on the curb side. If I could contact Winnebago directly and ask them, I'd feel better. I may just have to put a ventilation type screen found in a marine store. I see my shower is about where yours is. Do you have moisture problems in that basement compartment, below the shower?

[ChasA]

I have two antennas on the roof, one up front for the in-dash radio and one just aft of the shower skylight for the outside radio. It was the one near the shower that was leaking. Since I tightened the rear antenna, the compartment under the shower has been dry. Before cutting a hole in my coach, I would check judiciously for leaks somewhere above the wet compartment. Good luck.
Chas