if you locate the motor i e mine is behind the molding on the slide out at the top.. use a multimeter at the last two wires to touch the motor.. unplug them and put the probes in each wire get good connection,, set the meter and have someone turn the switch to the slider,, if your reading is 12 v or more than all is good from that point,, if not then work backwards ,, if reading is 12 v or 14 v then yes motor could be bad,,, check for binding also .. good luck .. kennyg