Thinking about it, I'd be tempted to remove the glass completely and first drill only one hole and get the pump blowing in then go all around the seal with soapy water until you find where it's leaking and seal that up or the moisture will get in again.
Assuming that your glass is fitted from inside, I'd then refit it with only 2 of the plastic trim/retaining pieces, lets say both the sides and drill the second holes so that it will be hidden when you refit the bits of plastic after you've had the pump running and then sealed up the holes after drying out the window.
One of the 3 in units in my garage has failed, I might have a go at this... If I do I'll report back.
Assuming that your glass is fitted from inside, I'd then refit it with only 2 of the plastic trim/retaining pieces, lets say both the sides and drill the second holes so that it will be hidden when you refit the bits of plastic after you've had the pump running and then sealed up the holes after drying out the window.
One of the 3 in units in my garage has failed, I might have a go at this... If I do I'll report back.