Leveling system [1996 U270, no power to aux compressor]

Topic: Leveling system [1996 U270, no power to aux compressor] (Read 577 times) previous topic - next topic

Leveling system [1996 U270, no power to aux compressor]

February 24, 2023, 11:06:33 am

Need some help, compressor bench tested fine got power to control box on red wire but no power going to compressor?
1996 U270
All fuses in control box tested fine.

[edit topic title to be more descriptive - Michelle]

Re: Leveling system

Reply #1 – February 24, 2023, 11:22:04 am

I have a resettable breaker for the compressor in the main bay under the white fiberglass cover.

Re: Leveling system

Reply #2 – February 24, 2023, 11:46:07 am

All circuits test good

Re: Leveling system

Reply #3 – February 24, 2023, 11:58:40 am

Your coach has a lot less resettable breakers than mine. I guess you will have to trace the wire
backwards to find the fuse or breaker unless someone with the same coach can come up with
the answer.

Re: Leveling system

Reply #4 – February 24, 2023, 01:02:02 pm

Quote from: oldguy – February 24, 2023, 11:58:40 am

I guess you will have to trace the wire backwards...unless someone...can come up with the answer.

Voila!

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #5 – February 24, 2023, 03:53:34 pm

Not having much luck finding anything that feeds power to black wire on front of compressor 🤷🏻‍♂️

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #6 – February 24, 2023, 05:24:27 pm

So relay has power to it but the control small wire is not powered. This is powered threw the HWH level to tell compressor to turn on during level requests. You dont have a slide.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #7 – February 24, 2023, 06:04:25 pm

The trigger wire comes out of the control box to the pressure switch then to the relay (solenoid) excite terminal was the information I got from talking to a HWH tech.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #8 – February 24, 2023, 06:48:17 pm

Quote from: dsd – February 24, 2023, 05:24:27 pm

So relay has power to it but the control small wire is not powered. This is powered threw the HWH level to tell compressor to turn on during level requests. You dont have a slide.

No slide , rear pressure switch is what it's sounding like that sends signal to turn on pump if I'm reading wiring schematic correctly

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #9 – February 24, 2023, 06:57:16 pm

Quote from: Washingcars – February 24, 2023, 06:48:17 pm

No slide , rear pressure switch is what it's sounding like that sends signal to turn on pump if I'm reading wiring schematic correctly

Just trying to verify that control wire to start pump comes from rear pressure switch ?

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #10 – February 25, 2023, 09:25:11 am

There is a print just for the compressor control. From memory (Ha Ha) I recall it has its own pressure switch on the compressor which is field adjustable under the cap, but also uses a override function with the HWH to turn the compressor on anytime the HWH control panel requests a change to level. This is regardless of pressure and strictly a command for compressor to turn on during releveling.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #11 – February 25, 2023, 10:12:04 am

Good morning
Don't have print just for control board , prints I do have don't label trigger wire or color.
My thoughts are with no air in lines trigger wire should be getting signal all the time from somewhere .

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #12 – February 25, 2023, 10:50:23 am

Quote from: Washingcars – February 25, 2023, 10:12:04 am

Good morning
Don't have print just for control board , prints I do have don't label trigger wire or color.
My thoughts are with no air in lines trigger wire should be getting signal all the time from somewhere .

The single wire plug coming out of the control box should have 12v to the pressure switch at the compressor then to the exciter wire at the relay. This wire is only hot when the controller is calling to level not continuously.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #13 – February 25, 2023, 11:09:20 am

Two separate requests by the coach. Low pressure and compressor ON for leveling regardless of pressure.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #14 – February 25, 2023, 11:23:49 am

Only getting power on 2 wires , red power wire feeding control box and white wire going to top relay terminal on compressor.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #15 – February 25, 2023, 12:33:21 pm

Quote from: Washingcars – February 25, 2023, 10:12:04 am

Don't have print just for control board , prints I do have don't label trigger wire or color.

Do you have this manual for your coach?
https://www.foreforums.com/index.php?action=media;sa=media;in=1457
Page 19 should help

Mike

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #16 – February 25, 2023, 01:40:35 pm

Thank you Mike, didn't have that one but I do now 👍
The compressor harness from control box (black) 9700 is where I have lost my oars, no signal from control box .

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #17 – February 25, 2023, 02:54:22 pm

Quote from: Washingcars – February 25, 2023, 10:12:04 am

My thoughts are with no air in lines trigger wire should be getting signal all the time from somewhere .

Just got caught up on this thread as I have a few irons in the fire.
Go out and find the pressure switch that is on the bottom of the rear 6 pack. Once located unplug the connector and use a jumper wire to jump the 2 wires together that come from the front. Either the compressor should run, blow fuse, or let some smoke out.

Mike

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #18 – February 25, 2023, 04:08:14 pm

Thank you Mike, I will do that in the morning after blocking and let you know the results .

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #19 – February 26, 2023, 08:30:04 am

Good morning Mike
Cleaned up the connections n made direct connection between 2 wires nothing changed, all fuses still good.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #20 – February 26, 2023, 10:29:45 am

Go to the link in reply #15 then go to page 12 and start trouble shooting.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #21 – February 28, 2023, 10:35:46 am

Update to my leveling system compressor, no power to 3 pin compressor plug in the box .
Control box needs replaced.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #22 – February 28, 2023, 01:21:44 pm

You need to contact HWH and get a R/A for the board. They rebuild those at a fair price. It could be as simple as a cracked solider joint.

Mike

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #23 – February 28, 2023, 01:54:53 pm

Thank you Mike , I'm in Florida till the end of March and will get it sent in when I get back home.

Re: Leveling system [1996 U270, no power to aux compressor]

Reply #24 – February 28, 2023, 04:02:37 pm

We found our 1997 U270 HWH's small compressor of little value as it did not have the 'umph' to lift the heavy rear, so we kept it turned off all the time. This system was designed to only power the compressor when the dash HWH panel is on, air pressure sensor finds captive air pressure too low, and a front or side is too low.

In fact, after leveling with engine running (to get air pressure), when the ignition was turned off, the HWH automatically turned off with our HWH configuration. HWH constantly made changes on how they work.

I would not rebuild or replace control unit for this reason. You could put a dash switch to manually run compressor if you think it will help.

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