2004 Newmar will be Newmar designed Slide motor and mechanism. There are a few things that will cause your problem. The Lock arms are bent and jamming the slide from fully closing. The Motor Intellitec controller is either defective or needs its amp draw pot adjusted. The motor itself may be defective and is drawing too many amps and causing the Intellitec motor controller to amp out and stop operation. If you have a slide cover, have you checked to make sure the slide cover is not rolling correctly and jamming the last 5 inches? Usually the Motor Intellitec controller for the rear slide on Newmars is located in the Mid bath area cabinets. ALL parts are Newmar supplied except you can get the controller from other RV suppliers. This link shows what the controller looks like. Doug
https://www.camperid.com/intellitec/control-module-mpn-00-00525-310.html?view=298508&gclid=CjwKCAjwhOyJBhA4EiwAEcJdcUp6brv73xHgR2nL2s_1H2HfbFdMHR0t7-ppQ-XvTHrBfVwfyAg9pBoCh1EQAvD_BwE
