Hello & Welcome Bitafun2:
Welcome to IRV2. Yes the brake lights should work off the Motorhome.

Since you purchased the CR-V already equipped to tow you are going to have determine how it is wired first. You should also check your Motorhome wiring to make sure it is working properly. After I checked the MH for power than I would check the Umbilical cord for broken/disconnected wires. If they checked out OK than it is time to check the tow car remember you may have two light bulbs or they may have used diodes and one (Light/Diode) may be bad. I hope this info is useful.
As far as your BB I am sure someone that has one can help you. You maybe able to download the instruction manual off the web.