I have a 2002 Holiday Rambler Ambassador and I have been chasing this same issue for quite some time. The other day I finally got into the dash and I found the chassis ground terminal had many loose grounds connected. Also, when inspecting the headlight switch the ground wire connected to it was loose — almost being pulled out of the switch itself. I pushed it back in all the way, removed, cleaned and tightened all the loose grounds I could find and mine hasn’t flashed intermittently since.