Remove wood looking center dash piece the radio is in. Only 4 screws hold it in place. Gently pull this part back out of the dash while watching A/C hoses and wires. Once you can get your arm inside this space look with flashlight to see a wood brace running about 2 inches under plastic dash top.
Go to Lowes and buy two LARGE rubber door stop wedges and some Gorilla glue gel.
Spread the glue all ove top of a wedge and jam it between dash and wood brace. Hold until the glue sets. Do this two places as far apart as you can reach.
You will amazed how much quieter your RV rides without the dash bouncing around!
2015 Jayco Precept 35UN
Towing JEEP TJ with Roadmaster plates and bar w/Blue Ox Patriot brake
an Aluma low bed trailer with HD Road King and/or Polaris RZR onboard