How do you change the TopSurfaceInput of a motor?

Me and my friend are working on a light bar, but we cannot get some motor parts to spin? Here's the on script.

local car = script.Parent.Parent.Parent.Car.Value
local Lightbar = car.Lightbar

script.Parent.MouseButton1Click:connect(function()
Lightbar.BA.Light.Enabled = true
Lightbar.BA.Light1.Enabled = true   
Lightbar.BB.Light.Enabled = true    
Lightbar.BB.Light1.Enabled = true   
Lightbar.RA.Light.Enabled = true    
Lightbar.RA.Light1.Enabled = true   
Lightbar.RB.Light.Enabled = true    
Lightbar.RB.Light1.Enabled = true
wait(0.5)
Lightbar.BMotorA.TopSurfaceInput = Sin


end)

and a picture of the light bar itself: https://gyazo.com/cda8bb6ba4ed5de2bda1729eafaaee5d