2003 Fleetwood Revolution - turn signal problems

My Revolution has a similar issue. If my RV sits for a week or more, my signals also don't work. But what I have found out is, as soon as I start rv, I turn signal on and leave it on until it starts flashing. Usually takes 3-5 minutes, but it will eventually turn on. From that point on it works every time until the rig sits again for a week or more not being used.