I run mine out for 15 seconds. Run it back in until I hear major clunk. My coach has the electric operator. Don't know when WRV changed from hydraulic. Had an incident on the freeway the prevented slide from complete retraction. Could not find a sensor so drove from Barstow to LA with buzzer going off. Later found there is a magnetic switch on the driver's side of the cowl that is actuated by a steel disc on the fibreglass front panel.
Rick J Fisher, BW is Judy
2007 Alpine 34FDDS Limited SE
2003 Jeep Rubicon or a 1995 Toyota Tacoma