Things You'll Need
Spray cleaner/lubricant or penetrating fluid
Metal lubricant (optional)
Jalousie windows are commonly found in tropical locations, such as Hawaii and Florida, and in mobile homes and RVs. They are crank-operated windows with horizontal slats of glass that lie flat against one another in the closed position. The slats are held with metal brackets that pivot to open and close the window. The brackets and the crank mechanism that controls them commonly stick due to dirt, grime and corrosion. Cleaning the metal parts usually gets the window moving freely again.
Check the outside of the window to ensure nothing is blocking the slats, causing them to stick or disabling the crank. Also look for sticky substances on the glass slats to make sure they aren't stuck together.
Open the window a couple of inches, if possible, but do not force it open or attempt to open it all the way, which may stress the parts unnecessarily.
On the inside of the window, spray the crank mechanism and all moving parts liberally with a cleaner/lubricant spray, such as WD-40 or brake cleaning fluid. Pay particular attention to the pivoting joints on the slat brackets. Allow the fluid to penetrate for 10 or 15 minutes. For severely stuck or corroded metal, you might have better luck with a penetrating solution, such as penetrating catalyst spray designed for marine and automotive repair.
Wipe all metal parts clean with a cloth. Use an old toothbrush or a cotton swab or toothpick, as needed, to remove grime and corrosion from tight areas, then wipe again with the cloth.
Open and close the window carefully, keeping an eye out for sticking points in the mechanism and slat brackets. Reapply the spray cleaner/lubricant and wipe clean any problem areas, as needed.
Lubricate the joints of the metal parts, if desired. Lubrication is optional and comes with some drawbacks. It's messy and can stain curtains, and it attracts airborne dirt and other contaminants, leading to more grime and eventually hindering window operation. If you use lubricant, choose a non-greasy, non-oily formula that's compatible with your window's metal (aluminum is typical). A dry, lightweight wax-based lubricant may work best.
Use caution when working with jalousie windows to avoid breaking the glass slats. Because these windows are often found in older homes and vehicles, replacement parts can be difficult to find.