The simple answer is, you seem to have 2 slide rooms. the 5100 wire is for slide room 1 retract solenoid. 5101 is for the slide 2 retract solenoid. You should be able to read those numbers on the quick connect wire harness at each solenoid. Now if you have 2 slide rooms you have 2 extend and 2 retract. The Retract are above the motor. Looking at them from the T handle side, the right is room 1 retract and the left is room 2 retract. The solenoids for extend and retract are 180 degrees on each side of the manifold. Replace the bad retract solenoid. Do not attempt to rebuild or replace the O rings. This is the 1.5 inch solenoid replacement. Doug
RAP90729