You can click on the link below at Solar Sellers that sell transfer switches to see what one looks like. Usually they are located under the bed or in the case of our coach under the cedar chect at the foot of the bed when the slide is extended. Mine went out last year and I replaced it and also repaired the old one by replacing the time delay circuit board.
Ron
http://www.solarseller.com/iota_auto...tm#its___50_r_