2007 keystone challenger 5th wheel bedroom slide out does not close. how I isolate and resolve the issue

The bedroom slide will have the motor mount on the floor of that slide. If it has the bed on it, look under the bed and hidden for panel. If the is a dresser or other type of cabinet, you may need to remove the bottom drawers or other cover to access the motor. If you have the original handle set, one should fit directly on the end of the motor to hand crank. If not, find the end of the motor that is sticking out, a shaft with pins on either side or possibly it looks like a hex bolt. If it is a hex bolt, find the matching socket and ratchet (or small impact driver) to manually open/close. If the shaft with pins, two a couple pictures and measure the shaft length and diameter and take that into to a camping store near you. They may have a universal wrench made for the slide or have to order one.

Look for help on Google by searching for the make and model of slide mechanism. Most manufacturers provide troubleshooting and service help, and emergency retraction instructions.