HWH aux pump

Topic: HWH aux pump (Read 914 times) previous topic - next topic

HWH aux pump

July 21, 2016, 01:29:21 pm

My GV aux pump is new.

It runs for several minutes then the fuse in the wet bay trips and the fuse housing is hot. I have never figured out this system can someone tell me how this pump is supposed to function and why it could be tripping the fuse. The pump says max draw 18 amps and the factory fuse is a 15 amp. The airbags on the coach after sitting for 2 weeks were deflated and with the pump running it was adding air to the bags. I checked the dash air pressure gauge and it read 0. I must also say my battery charger died and I am charging the house batteries as I type this.

Thanks, Woodie

Re: HWH aux pump

Reply #1 – July 21, 2016, 04:12:00 pm

Hey Woodie,

Let's look at your symptoms. GV aux pump is new. Fuse at pump (or circuit breaker at 12 volt panel in storage bay) tripping and hot = amps draw too high on that circuit. Question is why. I wonder if the motor on the new HWH pump is same as original pump? Perhaps a higher amp motor was substituted? You definitely need to figure out what is overloading the circuit, before you use the pump much more.

With the pump running, it is adding air to the airbags. This is GOOD! This is what is supposed to happen. You don't see any pressure indication on the dash air gauges, because the HWH pump sends its output directly to the 6-pack manifolds. It does not try to fill any of the air tanks (at least on the older model coaches, like yours and mine). SO, not seeing pressure on the dash gauge is normal.

The HWH pump on our old coaches runs on 12 volt. If your coach (house) batteries are very low, it is possible the low voltage condition is causing the problem with the fuse/circuit breaker. Try it again when the batteries are fully charged?

In the meantime, here is some reading material for you to peruse. May take some of the mystery out of HWH pump operation.

Re: HWH aux pump

Reply #2 – July 22, 2016, 01:11:43 pm

Ok batteries are charged. I unplugged the pump reinstalled the fuse when I put the fuse in I heard a click which I assume is the selinoid/voltage regulator (pic below). I tested the voltage coming to the pump and it was 11.97. I touched the selinoid and it was extremely hot. I think that means it's bad?

Re: HWH aux pump

Reply #3 – July 22, 2016, 03:01:40 pm

What is the status of your HWH touch control panel while you are doing this? If the HWH leveling system is "OFF", you should not be getting a call for the aux pump to activate. If the solenoid is bad, as you suspect, it might be stuck in the "ON" position so the pump is trying to run constantly. Probably wouldn't hurt to check for continuity across the connections on the solenoid. It should be "normally open" until it receives a signal from HWH control box - then it closes.

Re: HWH aux pump

Reply #4 – July 22, 2016, 03:06:07 pm

Control panel was in the auto level function. Should it have been so hot? Also when I removed the fuse and put it back in you hear a clicking like it is opening/closing.

Woodie

Re: HWH aux pump

Reply #5 – July 22, 2016, 04:58:53 pm

IF your coach air system pressure is low (< 80 psi), AND if the HWH system is in "auto level" mode, AND if one or two yellow (out of level) lights are showing, AND if the system cannot achieve level by lowering a side or front or rear of coach, then the aux pump should be trying to run.

As for the "hot" solenoid - I don't think that is "normal", but can't say for sure. I have never had the need to "feel" any of the control switches/solenoids on our aux pump. Usually, when a electrical solenoid or switch feels unusually hot, it is not a good sign.

Re: HWH aux pump

Reply #6 – July 22, 2016, 06:24:25 pm

Quote from: leejrfla – July 22, 2016, 03:06:07 pm

Control panel was in the auto level function. Should it have been so hot? Also when I removed the fuse and put it back in you hear a clicking like it is opening/closing.

Woodie

Was the compressor running after you put the fuse in.

Re: HWH aux pump

Reply #7 – July 22, 2016, 07:24:47 pm

Yes

Re: HWH aux pump

Reply #8 – July 22, 2016, 08:28:06 pm

To find the problem, you will need a clamp on DC amp meter to see how many amps the compressor is pulling.

Re: HWH aux pump

Reply #9 – July 22, 2016, 09:12:13 pm

What do you think about the heat the solenoid was generating (Chuck is leaning toward it really seems like it shouldn't be that hot) with the wet bay fuse in and the pump unplugged? I will check and see what the pump is drawing.

Thanks
Woodie

Re: HWH aux pump

Reply #10 – July 22, 2016, 09:54:07 pm

I would be suspect about that hot solenoid. In your pictures it looks like maybe the casing is starting to melt. I would replace the solenoid based on being that hot alone. The heat would be caused by a poor connection inside and there should be no poor connection in a solenoid. You could also measure the voltage across the solenoid when it's energized to see the voltage loss. Should be less than .2 volts on the two big terminals.

Re: HWH aux pump

Reply #11 – July 22, 2016, 10:12:35 pm

My guess it's a bad solenoid. Remember, when a solenoid is energized, the coil receives a pulse of high inrush current which decreases as the plunger closes. If, for any reason, the plunger does not close, the high inrush pulse continues, and the coil overheats and burns out. This type of coil burnout is the most common cause off solenoid failure.

Re: HWH aux pump

Reply #12 – July 23, 2016, 02:54:16 pm

Ok, I got the coach air pressure up to 110 lbs shut down the engine reinstalled the fuse and made sure the leveling system was off. I reinstalled the fuse and pump came on and ran and ran until I pulled the fuse before it got to hot. I tested the pump and it was drawing about 8 amps when running does that make sense?

Woodie

Re: HWH aux pump

Reply #13 – July 23, 2016, 03:00:32 pm

Hi Woodie -

Are you a Motorcade Member - Premier?

Re: HWH aux pump

Reply #14 – July 23, 2016, 03:05:46 pm

Yes I joined but haven't been to a rally yet. Premier? I think so I do get a discount on parts at FOT.

Woodie

Re: HWH aux pump

Reply #15 – July 23, 2016, 03:10:47 pm

Sent you a PM. Give me a call.

Re: HWH aux pump

Reply #16 – July 23, 2016, 03:56:36 pm

Chatted with Woodie for a while.

I suggested he contact the RV service company that recently replaced his Aux Compressor as well as James T. and HWH to review his situation for additional trouble shooting suggestions.

He was going to check continuity of the solenoid on the compressor.

Re: HWH aux pump

Reply #17 – July 23, 2016, 04:06:02 pm

So I checked the solenoid and the meter did buzz. Not real sure what that means exactly.

Woodie

Re: HWH aux pump

Reply #18 – July 23, 2016, 04:28:03 pm

Quote from: leejrfla – July 23, 2016, 02:54:16 pm

Ok, I got the coach air pressure up to 110 lbs shut down the engine reinstalled the fuse and made sure the leveling system was off. I reinstalled the fuse and pump came on and ran and ran until I pulled the fuse before it got to hot.

SO, with 110 psi in the tanks, and HWH leveling system "OFF", the Aux pump should NOT be running. Since it is, something in the switching mechanism or circuitry that controls the pump is malfunctioning. The general opinion here seems to point toward the solenoid switch that is overheating. If you can find a suitable replacement for that solenoid, I would say change it out.

Being the weekend, there's not much chance you will get in touch with any kind of "official" tech support. (We don't count) If Scott was giving you some tips on checking the solenoid with a multi meter, perhaps he will explain the significance of the "buzzing".

Re: HWH aux pump

Reply #19 – July 23, 2016, 04:35:10 pm

The meter buzzed not the solenoid when I check continuity.

Woodie

Re: HWH aux pump

Reply #20 – July 23, 2016, 05:46:08 pm

I presume that the buzzing from the DVM means that there is continuity in the solenoid. My suggestion to Woodie, since they are not underway, that calls might be made for support and get some more professional input early next week.

He recently had his aux comp replaced recentl at a central Florida repair center. I suggested he make that call first. Not to accuse but to share what is happening with them. They are HWH certified and might be able to solve his problem.

FWIW.

Re: HWH aux pump

Reply #21 – July 25, 2016, 01:51:25 pm

Ok, So I was able to locate a new solenoid for the Aux pump the old part name and part # is Essex 120-105111 the replacement part name and number today is White Rogers 120-901 it was like 32.00 and change when it arrives I will post more details. In the meantime (terrible picture) but what is the cylindrical item next to the pump it says Parker on it has a brass fitting on the bottom with two wires coming out of it.
Thanks
Woodie

Re: HWH aux pump

Reply #22 – July 25, 2016, 02:13:54 pm

Quote from: leejrfla – July 25, 2016, 01:51:25 pm

...what is the cylindrical item next to the pump it says Parker on it has a brass fitting on the bottom with two wires coming out of it.

Yes, the photo is terrible.

Cylindrical...Parker...brass fitting...2 wires. If you will refer to the link I posted in reply #1 above (HWH 600 Series Service Manual), you will find a very clear diagram of the aux pump assembly. There is only one item that matches your description. My guess is the Water Separator with the "Normally Open Air Solenoid" located on the bottom. Look at the drawing in the manual - look at your pump - decide for yourself.

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