Rather then trying to pull a fuse, have a charge wire installed from the Coach to the CRV, that way the coach alternator will keep the CRV battery charged as you drive. Easy to do, run a wire from the Coach battery, install a self resetting breaker close to the battery, back to the 7 way, run a wire from the 7 way to the CRV battery and install another breaker close to the CRV battery. My 2002 CRV has been towed for 13 years without a dead battery because of the charge wire.
Follow the shifting procedure in the CRV owners manual to a T every day you tow and you should not have a probleem