Replaced our original HWH level sensor with a new style electronic level sensor. It is mounted centered between front & rear axles and side to side on our big bay's ceiling. I ran the cable to HWH control box above house battery compartment.
The original level sensor was fastened to the floor under a kitchen cabinet and used mercury to sense when coach was not level. HWH panel indicated level sometimes when we still off a little. I did improve it a little by adjusting the original level screws. HWH converted to electronic level sensor, partly because the original used mercury.
After mounting new level, I just unplugged original sensor, plugged in new sensor and made a new power connecton
HWH parts RAP-91734 (cable kit) and RAP-91031 (sensor) cost $300 and also included AP-30631 (short 12-volt power harness) and AP-29299 (three bolts & springs to mount sensor).
Initial one-time adjustment is simple. We will report if our leveling is improved after we hit the road.
Updated March 2014 Replacing Original HWH Level Sensor with New Electronic Sensor (http://beamalarm.com/Documents/hwh/replacing_original_hwh_level_sensor_with_new_electronic_sensor.html)