Hi Dave,
See this pic of one of mine. This is from a 2004 but your 2003 should be the same. It yours looks nothing like this, please post a pic. This window below is in our bath which is why the glass is pebbled but all the single hung windows work this way from this vintage of window.
There are 2 black tabs in the center of the window. Those tabs both push in towards the center of the window which pulls a plunger pin out of the side frame (one for each side) to allow the bottom portion of the window to be raised.
The tab
On these up and down windows, only the bottom window opens. It raises up and there is only one screen. Technically they are single hung windows.
I suspect that you have figured out to push the 2 black tabs towards the center but the window will still not go up? Is this correct?
Odds are high that window is stuck down in the lower part of the frame. If they have not been opened in a while, they seem to collect dirt or something that makes them stick extremely hard.
If you make sure the 2 tabs are fully pressed towards the center and pull up hard, so far I have been able to get them open when they are stuck. Once open I spray some liquid silicone spray on a rag and wipe the inside of the track. This helps greatly.
The lower window will latch up when full open. You can see a hole in each frame side towards the top where the black plungers pop into.
If after trying to yank it open and it still will not come short of feeling like it is going to break, here is an option. You can remove the screen. To do this there are flat curved springs on one side of the window. If you press the screen to the side, the springs collapse and allow the screen to move over enough the other side will come out of the track. Then the screen comes out. On ours, I seem to push the screen to the right and it moves over. If I push it to the left and it does not move very much, then I know to push on the other side as only the spring side will compress. I never figured out yet if all springs are always right side or not. So try the other side if yours does not move on the right side.
Once the screen is out, you can spray in the crack between the lower window and the frame channel with some silicone spray or other penetrating liquid to help break loose the tight fit.
Hope this helps. If you need more on this, just ask away. Odds are high you can get it open now that you know it may come up real hard the first time.
John
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Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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