Small crack from window

The goal is to prevent the crack from growing.

If it is a plexi-glass (plastic) window, the solution is very simple. Just drill a small hole maybe 1/8" diameter into the end of the crack to stop the crack from growing. Then fill the hole with a clear caulk. The crack itself will let in so little water than you'd have a hard time seeing it. It would evaporate before it hits the floor.

The same applies to tempered glass but that would best be handled by a professional windshield repairman. He too will drill a hole using a special bit with a Dremel tool. He will use a special made-for-glass sealer. His hole will be so tiny that you'd need a magnifier to see it.
I stopped a windshield crack from growing on a 1971 Oldsmobile windshield back in 1979, but it was primitive and ugly. I used a brass rivet as a hollow drill bit, and used grinding compound as the abrasive. I don't recommend it for it was a very long and tedious process that looked like I did it.

Side small window, bathroom window

cdb7777 wrote:
I have a crack on the side coming from window about 1.5 inches can I repair it myself. I'm only interested in stopping water from getting inside wall. Super glue etc.

I'm not clear on your question. Is a side window cracked, is the side of the RV cracked or is the windshield cracked?

If this is a side window. I would use Dicor Non-Sag Lap Sealant. You may want to drill a small hole at end of crack to help stop crack from continuing beyond where it has already gone.
While doing the repair you may want to look at why crack started at window.

First, check with your auto insurance company. Often times windshield repair is free, while replacement might have a $50 - $100 deductible.

Most auto parts stores sell repair kits.

-Michael