Well, great news. I was playing around with the system yesterday and decided to try and spin the pump over. I went to Home Depot and bought an adapter for my cordless drill that was meant to install "I" hooks. I spun the pump the direction the electric motor was spinning an nothing happened as expected. However, when I reversed the direction, I felt a load on the drill after a few seconds. So, I removed the "U" shaped tube by the shuttle valve and tried again and WOW, fluid came out. So I hooked the tube back up and reinstalled the motor. (The prior owner had the RV worked on at a dealership and they replaced the electric motor and had concluded it was probably the pump that was the cause of the jacks/slides not working).
I then reversed the positive and negative wires on the motor, checked for any issues, then turned the power to the RV on and tested the jacks. I was SHOCKED to hear the jacks coming down!!! Three of the jacks came down. I need to check on the fourth. I then went into the RV, heart pumping with excitement, and tried the slides. AMAZINGLY, both slideouts worked!!!! I was in shock since I have never seen the slides or jacks work. It was a very exciting day.
Anyways, it's still hard to believe the dealership installed the power leads incorrectly. I never originally considered that but am happy to have everything working.
Thanks again to everyone for their help on this.
