HWH pump sporadically won't run

[Cinequip]

Looking for opinions on my intermittent HWH pump failing to start at times. Here is the scenario: Today I opened a smart bed a little ways before realizing it was the wrong bed. When I went to close it, I just heard a relay click from the service bay. Tried the other switch, and got relay clicks on both open and close. Because I was in a parking lot, I decided to drive home with the smart bed slightly open, and work on it there.

At home tried the close switch again with same result. Went to the other side of the coach to try those bays. Initially got clicks, then finally the pump ran. Went back to the original bay, which now ran the pump and closed. All HWH systems working fine now.

This has happened one other time in the last few months. Here are my possible guesses: HWH motor commutator wearing out, or dirty contacts in motor contactor. Given that when this happens, ALL HWH operated devices don't work, it's not individual device switches.

Anybody else experienced this or have any other suggestions? I'm about ready to order a spare HWH motor to carry.

[JLMunsil]

I would check the ground wires to motor and solenoids

[EngineerMike]

On mine it was the pump relay. Two solenoidish looking thingees on HWH pump, one is Main relay, other is Pump. I remote mounted the new Pump using a Cole-Hersee 24059 solenoid, so I could get at connections easier; will remote mount the Main similarly when its final day comes. Perfect track record since I Cole-Hersee'd it.
Could also be any other connection up the point you hear the click (i.e. its in the HWH bay).

[HicksRA]

Grounds, Grounds, Grounds. Check all your grounds......

[Koop]

I agree with checking connectors and grounds - but here's an easy first check you can do. At least it was easy on our coach. If you can access the motor, have Marcia hold the powered up HWH switch in the close position. While she's doing that, rap on the motor with a hammer. If the motor starts running, you have a bad motor.

We recently went through this. I did a lot of voltage drop and continuity checks. I wish I would have just done the old Chevy starter motor trick first. Our motor started running for a few seconds every time I whacked it with a hammer. Replacement motor solved our problem.

Scott - you might want read what I posted about this issue on our blog last month here.

[RogerBall]

I had been experiencing the same intermittent pump motor operation whenever I selected a smart bed or tried to move a slide. It had been getting progressively worse. Thankfully, the HWH Service manual provided some excellent troubleshooting tips.

It say's when you push a smart bed or slide switch a signal is sent to a couple of low current relays mounted on a circuit board which in turn provide drive current to the solenoid coils mounted on the pump assembly. The manual refers to a couple of LED's that indicate proper or improper operation of these relays. Each relay has two LED's. One is yellow and one is red. The yellow LED indicates when a relay is selected. The red one indicates if the selected relay is outputting current to the solenoid. If the relay is operating properly, both LED's should be lit when a switch is pressed. If only one LED lights then you have a problem.

After observing the LED's while trying to operate the smart beds, it became clear that I had a defective relay. Only the yellow LED would come on, no red LED. I could get it to work if I tapped it with a screwdriver handle. Under these conditions, the manual say's to replace the whole board but that seemed to be a bit extreme. Since I have a bit of experience with electronic repair, I decide to replace the relay myself. I was able to locate replacement relays from Mouser Electronics for about $2 each. The Mouser part number is: 817-FBR51ND12-W1.

The actual replacement was very straight forward and I'm happy to report that so far the pump has started every time. Time will tell.

Not exactly a DIY project but anyone with some soldering experience (Heath kit type) and a good desoldering tool should be able to facilitate the repair. Or maybe use an electronic repair shop (TV type) if you can find one.

I've attached a video of the tests and relay replacement process.

Hope this is helpful.

[Renipladlo]

All Good Suggestions, but are you using the outside switches on the coach, or are you using the switches on the HWH panel for the PS side beds, and the ones on the DS side in the services bay? The OEM switches on the outside of the coach are garbage and failed on my rig 3 months after we purchased. The ones in the bays have worked flawlessly since I had to start to use them. Otherwise, I would do the other checks.
All however is not rosy on mine, I have some Hydraulic lines I need to change and don't have a clue how that is done. Guess I will use the Columbus methods, discover and land.

[Basil Shannon]

Roger, interesting about SE Smart-Bed operation via the HWH circuit boards. WRV must have changed the design from my early Apex which was entirely hardwired. At Least that is what I found when I spent MANY hours ringing out 75598. Could be wrong but here is what I wrote down in 2011:
SMART-BED OPERATION

Looking at the 2000 series HWH owner's manual wiring diagrams which apply to the Apex model and the SE model as well (partially), here are some points about the operation of the Smart-Beds:

The Smart-Beds are totally independent of the Silverleaf system. On the SE & Apex coaches, there are four WRV supplied DPDT switches (one for each Smart-Bed) that are hardwired to the HWH solenoid valves and the coil of the pump relay. When a switch is pressed to move a Smart-Bed, one side of the DPDT switch applies power to open the HWH solenoid valve and the other side applies power to the coil of the pump relay. Valve opens, pump comes on and Smart-Bed moves.

Note also that the Smart-Beds are independent of the HWH circuit boards. HWH provided the solenoid valves and WRV hardwired them to switches.

Apex coaches offer a second way to operate the Smart-Beds. WRV installed touch pads which were unreliable and most owners have replaced them with rocker switches. These touch pads or switches apply power to the coil of the appropriate one of eight relays, one for each bed extend and retract. These relays are mounted on the forward wall of the hydraulic compartment on my coach.
WIRING DIAGRAM ATTACHED. WRV had a gazillion splices in the hydraulic compartment and miles of excess wire. Changing hydraulic pumps is a nightmare.

[azpete]

if you are going to the alpine rally in quartzite, im doing a seminar on hwh there on jan 15th. i will have parts, but i cant do repairs because of new blm rules.
my cell is 602-549-3638.
it sounds like the pump relay rather than the motor.
paul maddox