I found the same thing with my Jalapenos last season. I waited a Long, long time for them to finally get red and they never did and they never grew beyond a certain point. I would say I had some jalapenos at mature size for 5 or 6 weeks that never turned red. I finally harvested them all at the end of the year.

This year my plan is to harvest a lot of my peppers when they get mature size and not wait for them to turn red/orange. Such as the banana peppers and Hot hungarian wax. Of course, I will wait on the super hots and probably cayennes as well to fully ripen. I think it will allow more production to pick them in their pre-ripened stages.

It might just be that Jalapenos simply take forever to fully ripen.
Bruce

Thanks for your input, Bruce. I picked most of the jalapeños and Hungarian peppers. I also picked two poblanos and a green cayenne, mostly because I was curious :)

Not too shabby there! Jalapenos will "cork" while green, that's when I harvest. They do seem to take awhile to go to red.