figure out a way to pressurize the inside of the moho. some ceiling exhaust fans are reversible. maybe the heater blower on fresh air would be enough. or use a vacuum cleaner on blow with a cardboard adapter in one of the windows.
then spray a soapy solution from outside where you suspect leaks and look for bubbles.
i didn't figure this out by myself. there is a thread in this forum that deals extensively with water leaks and i filed this info for future use.
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