Replacing cord on double hung windows
I'm hoping someone can help me because I'm really at a loss on how to proceed. First, I can say that I am pretty handy with most household repairs, construction, etc. So no problem in that regard.
The cord of one of the double hung windows in my girlfriend's apartment snapped. I obtained some new cord, found a procedure on line for removing the vinyl "track" in the window frame, removed the sash and expected to see a "lid" of some sort, wood or metal, with a screw that I would remove. Once the lid was removed I should find the counterweight and from there I could proceed with replacing the cord.
Unfortunately, I found no lid of any kind. Another very hand friend also took a look. We removed the trim from the front of the window and couldn't see anything that way either. We are completely at a loss for how to access the counterweights and cord to repair this window. I'm not absolutely certain, but I believe they are Anderson windows, they are wood, and probably about 20 years old.
Any help would be greatly appreciated.