Tag axle switch = nothing

[IEMan 1]

Travelling across the country.  My tag axle switch stopped working. It was working fine when I slowed down, the light would come on the switch and the tag would raise. All of the sudden the light does not come on when it should and tag not raising. 

Does anyone have any ideas what I should check 1st? Hopefully an easy fix while travelling.

[vito.a]

Some suggestions.  Make sure you're stopped or under 5mph, neutral or 1st gear, and house power on.  Also, it may not visibly lift the axle.  It may just barely take the weight off.  

From the manual:

The tag axle raises in the following modes:
• Interior house power must be ON.
• When the switch is on and the transmission is in Neutral, Reverse or
First Gear.
• With the tag axle in the up position there is not a specific height
requirement other than the tire should be off the ground.
Tag Axle Switch On:
• The tag axle switch supplies 12 Volt DC to the air valve located at the
roadside rear.
• The rear air valve applies air pressure to both tag axle lift chambers to
raise the axle.
• Air pressure in the tag axle air spring is released. The tag axle remains
up in reverse, neutral, first gear or until the switch is turned off.
Adjusting the tag axle load:
Changing the amount of weight carried by the tag axle affects weight
distribution between the tag, drive and steering axles. The amount
of down force applied to the tag axle is controlled by the amount of
air pressure in the tag axle air bags. An adjustable pressure regulator
located in the engine compartment sets the amount of air pressure in
the tag axle air bags. Regulator pressure is preset at the factory and may
require adjustment to obtain the proper weight distribution on all axles.
To determine the correct setting of the pressure regulator, weigh the
motorhome after it has been loaded for travel.
NOTE:
The tag axle pressure regulator valve is located in the engine
compartment on the roadside.

[Ivan K]

What kind air leveling you have, or do you? My tag lift is incorporated into HWH system and uses sixpack valves to dump tag bags and Mac valve to fill the lift canisters. Number of potential failure points, including a FRB fuse and the switch itself so it depends on what exactly is or isn't happening. Easy to troubleshoot while stationary. Does it do anything at all, does it dump but not lift, is it trying to lift but not dumping etc. BTW, it takes a while to lift so I stop and wait for it before taking that sharp turn, otherwise I am past it when it finally lifts.

[WayneC]

The tag on mine operates same as Ivan's and the audible alarm let's me know it is in the raised position. 

Wayne 

1999 Signature ceaser 

[IEMan 1]

Hi Again, I do have the HWH leveling system. 

When the tag should go up, nothing happens. No air dump, no movement, no light on the switch and no audible alarm. 

My leveling system works as it is supposed to.

What interior house power must be on? The inverter?

 

Thanks,

Dave

[Tom Cherry]

26 minutes ago, IEMan 1 said:

Hi Again, I do have the HWH leveling system. 

When the tag should go up, nothing happens. No air dump, no movement, no light on the switch and no audible alarm. 

My leveling system works as it is supposed to.

What interior house power must be on? The inverter?

 

Thanks,

Dave

Negative to “house” power or inverter.  Read Ivan’s post again.  Read your manual as well as finding the prints for the FRB.  IF the Leveling is working OK, then odds are the signal that raises and lowers the tag is not getting to the solenoid in the rear.  Check the fuse chart or”legend” in the FRB.  FIND the solenoid in the rear that controls it and cycle the switch and test for voltage.  The HWH prints should show the outgoing signal (or maybe two. Lift & Retract).  Then you can see if there are fuses as well as any (or none) relays in the circuit.  Then you can test to see if the signal(s) are being sent out of the unit.  Some folks have found that the large plug in connector on the bottom of the control box will vibrate loose and strange things happen…even after that, there is a master reset, which the service techs do might be necessary.

YES…this sounds complex….but until you start with the simple things like fuses and maybe relays and physically verify connections at the solenoid, doing all sorts of shotgun fixes can actually make it worse or have to have it reinstalled, setup and tested…

Download the manual or find it in your “briefcase”.  

[Ivan K]

I can only speak about how our 2000 (HWH600 series) works but the Tag lift function needs accessory power ON (chassis battery), meaning ignition key in run or ACC position. Inverter isn't involved. I'm sure your FRB is wired differently but I have a fuse on chassis side fuse block specifically for Tag lift. 

[Tom Cherry]

Google is your friend. Try “HWH TAG AXLE NOT WORKING”….many hits….  Look at them.  This was one of the first I read….keep reading and digging….

https://www.irv2.com/forums/f115/tag-axle-won-t-lift-481484.html

 

 

[Ivylog]

Haven’t raised my tag in 10+ years except to change the tires. Very little difference in turning radius and our tires age out before they wear out. Standing next to the tag, do you hear a air leak? If so, it’s like a blown rubber diaphragm in the raise cylinder… easy to replace.