Do your jacks work as often they use the same pump as the slides. Try pushing the switch several times... 10 to see if you can get the solenoid to engage. Usually the pump and solenoid valves are under the steps and there are several fuses there. They are bad about not working because of water/corrosion getting to them. Check the one for the pump motor.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45โ...