This is from the Motorhome Magazine 2012 Dingy Guide for the Honda CRV: Suggest downloading it - lots of infomation about towing.
Run engine at the beginning
of each day, press brake pedal
and move shifter through all
positions, shift into
DRIVE and
hold for 5 seconds, then to
NEUTRAL
and let engine run
for 3 minutes. Repeat at least
every 8 hours thereafter.
When towing for long
periods, remove 7.5-A
accessory radio fuse.