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HWH compressor

December 28, 2020, 03:27:51 pm

I have the big ugly projects out of the way, and I am working my way down the "Category 2" list.

The HWH pump...  If I understand correctly,with ignition on, engine off, HWH panel on and set to level, I should have a running compressor IF there are red side indicators on the panel.

I have power on the "hot in" of the relay at the pump, but no power out.  I have no power on the black trigger wire at the solenoid, so that suggests something up-line.

When I short the "hot in" and "power out" of the relay, the compressor runs, so that would seem to verify that the compressor is good,  so definitely something upstream.

A prior thread mentioned a fuse at the stairs labeled "HWH Compressor."  I don't see a label for that.  Do we know which fuse (resetting) it is?  Is there a fuse elsewhere?  I have checked all of the fuses in the HWH box, though they don't seem directly related.

Related to all of this, in the HWH box there is a connector labeled "COMPRESSOR BLACK FROM REAR AIR HARNESS."  Does that mean the wire goes to the compressor, or to the rear air harness?

I guess the main question is what do I do now?  The coach levels fine when engine is running, or when brake air tanks are filled, so this is far from emergency.

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Re: HWH compressor

Reply #1 – December 28, 2020, 04:49:43 pm

The compressor should only be running if you need air.  If I am level, I have 4 red lights on my control panel, one each f, r, l, and r.  If I am not level, I have a yellow light on the low side(s).  The coach will first try to level by lowering the high side which does not require the compressor.  If it needs to, it will pump up the low side and the compressor will run.

If you push any of the raise buttons, you should hear the compressor start running.

Can't help with the rest of your questions.

Rich

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Re: HWH compressor

Reply #2 – December 31, 2020, 12:06:13 pm

Thanks Rich!

It seems like I was pressing one less button or one more button than I should.  Compressor now runs, with no mechanical repairs on my part.

The black wire from the HWH box is the trigger wire for the compressor (+12v).  It first goes through the pressure switch, and then to the relay.  After the relay, it goes to the compressor.  I see no evidence of a fuse between the HWH box and the compressor.

I cleaned the moisture, debris bowl while I was in there.

What's next on the list?

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Re: HWH compressor

Reply #3 – December 31, 2020, 08:22:05 pm

Matt,  you may know this, but it took me a while to learn it.

When you push the button the first time on the HWH controller it is in manual level mode.  It will only raise and lower when you push buttons.

If you press the level button twice, it is in "auto level" and will try to stay level letting air out or adding as neccessary.

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