I have no idea but just thoughts come to mind.
Is the motor receiving power? Does it make a noise but not lower the bunk?
If no noise have you checked all fuses to make sure the motor is getting current.
Can the switch be accessed, unscrewed, popped out so you can check that it is even working?
Can you slide the mattresses out to gain access to the motor or access to the bolts holding the bed frame to the walls?
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2001 Suburban 4x4. 6.0L, 4.10 3/4 ton **** 2005 Jayco Jay Flight 27BH **** 1986 Coleman Columbia Popup