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Sealevel Ram · 11-13-2020, 07:08 PM

I recently had a failure of the air suspension system on my 04 Winnie Ultimate Freedom.

The system was repaired, with a new filter and governor, and all wheels pump up OK. I have driven it a couple hundred miles since the repair.

Only problem is the two air pressure gauges on the dash are not correct. They do not show full pressure, and the last time I started the coach one gauge reads 0 (yes, zero), and the low air alarm is sounding.

Service guy says the gauges are bad, and says bring it back to the shop.

Anyone else had this problem with gauges?

Ilvmygt · 11-13-2020, 08:20 PM

In most systems the gauge and alarm are 2 different components. The alarm is from a pressure switch which is separate for the gauge. The only thing that would be in common would be the air line that runs from the tank to the gauge and pressure switch. That would be more likely the problem and not both components failing at the same time.

Martind4 · 11-13-2020, 09:27 PM

We had a 2000 Itasca Horizon and a common problem was cold solder joints on the VDC (Vehicle Data Computer), which among other things converts analog air pressure to a digital signal for the air gauges.

Do a search for VDC and you'll find lots post about repair if that's your problem.

I think it's unusual for gauges to go bad, especially both at the same time. One thing that's common to both gauges is the VDC.

JFXG · 11-13-2020, 11:18 PM

Ram.... if you’re running on a Freightliner chassis it may well be the VDC as Martin mentioned above. I had this problem about 6 years ago. Intermittent flux of the air pressure gauges from nominal to zero, and back. Random aural low air alarm. This is a known problem with these vintage VDC units.
VDC is a smallish plastic box, about 6 x 6 inches, identifiable by the presence of both electrical AND red/green air inputs. Location may be variable depending on manufacturer. In my 02 Newmar it is located in the engine bay, on the passenger side wall about shoulder height. About a full arms length in from the back. May also be reachable from the bedroom/closet hatch, although not in mine.

Skip426 · 11-13-2020, 11:21 PM

2004 coach could be the last of those produced with the VDC.

Here's a pdf on the repair.

Sealevel Ram · 11-14-2020, 06:58 AM

I forgot to mention. I have a Spartan chassis.

FIRE UP · 11-14-2020, 10:19 AM

Well,
Being that the OP has a Spartan Chassis, this may, or may not apply. As an example, our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP, has a Freightliner chassis that was built in 10-'03. The coach was built in 12-'03. The coach was first put into service 1-'04. With a chassis build date of 10-'03, Freightliner ceased to use the "VDC". They started using a new and improved model labeled *MMDC*. Or, Multi-Module-Data-Computer/Controller.

And, while similar to the VDC in only one primary way, it's drastically better than the VDC. Yes, the Air lines from the air system enter the MMDC but, there have been zero ( at least that I've ever known or researched about) air transducer failures in an MMDC. Now again, this is primarily concerning a Freightliner chassis.

Just EXACTLY what Spartan used for engine, transmission, Air systems and ABS communications to allow drivers to monitory systems, in the OP's era, not a clue. It may or, may not be an MMDC or, something similar. But, also, not all coaches and or chassis operational components are the same. It's possible the OP may even have air lines that run directly to the gauges. Where as, in both the VDC and the MMDC, air lines run to those mini computers which, changes mechanical input to electronic output and sends signals to the air gauges. So, not sure on the OP's coach.
Scott