HWH 725 Leveling System - No Power

Are you getting power to the HWH touchpad but NOTHING WORKS???


Could be a number of things, but given the pump motor is not turning on, I’d start the diagnosis at the power source & relays. Links to the 40amp fuse kit & relays on our website can be accessed by clicking on the part #/description in these diagnostic steps:
 
  1. First thing to check is the 40amp fuse (RAP8539), which is near the power unit (pump/motor/tank). This is most likely at the front of your coach to the left (passenger side) after pulling out your front generator slide. These are notorious for being installed facing down, which can allow water/moisture into the rubber boot/cap & end up shorting out.
  2. If that fuse is good, then you need to check the main power lead (typically comes from chassis batteries, but could be wired to house batteries) that goes directly into the Master Relay (RAP38933) (it’s band clamped to the motor along with the pump relay). If you have good 12+V coming into that relay on stud #1, then check the power leaving that relay (stud #3) with your ignition in the ACC or ON position.
  3. If you DON'T have power leaving the master relay, most likely it is inoperable or stuck & needs to be replaced. You can tap on that relay to see if it will come ‘un-stuck’, but even if that gets things working I’d recommend replacing.
  4. If you DO have power leaving the master relay, you then need to check power leaving the Pump Relay (RAP35723) (stud #7) while the system is calling for pressure. Easiest way to do that is have someone else press an up arrow after the system is on, which is sending a signal to turn on the pump motor. If the Pump Relay is not sending power to the motor, then it most likely needs to be replaced.
These are the most common/simple issues to fix. However, there is still the possibility that the MIOM (Input/Output device) is not sending a 12v “trigger signal” to the relays. This can be checked by looking for 12+V power on the 8500 wire (stud #2) with the key on. And then the 8600 wire (stud #6) when the system is calling for pressure.
It could also be a motor issue. Easiest way to check that is to momentarily ‘jump’ 12v power to the + post on the motor & see if it runs.