Air Gauges, Bad or Not?

Thanks for the replies.

I forgot to mention. I have a Spartan chassis.

hughesjm21 wrote:
I had 02 Horizon with strange gage readings. Before replacing gages I called freightliner tech support. They had me replace a computer module (I cannot remember what it was called) in back of the coach. This solved the problem. It was not the gages. I suggest you call chassis manufacturer tech support and discuss problem with them.

I agree. Call the freightliner help desk ( 1 800 ftl help) and have the last 6 digits of your vin number available. Ask for the troubleshooting document for your gauges. The way your air pressure gauges work is two air lines going to the VDU (vehicle data unit), with resulting electronic signals being placed on the common chassis bus for the instruments.

Also, there were some solder issues on the VDU unit. There is a document on IRV2 forum that outlines how to repair. On IRV2, find the files section, go to electrical,and look for VDU/VDC repair.

I hope this helps.

Fred

What is the reasoning behind installing gauges? If the gauge does not read as expected, it's the fault of gauge? IMHO that is a dangerous fault in logic! If I was to look at the gauge in the garage now it would read 0, not because it's bad, but because there is no air in the system.

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

My old trucks set for a day or 2, I expect to hear buzzer, see light and a gauge reading 0. That told me I had a slight leak in the system. If it would hold long enough to meet the law just hunt for it while looking for other problems.
Now the not reading full pressure is a issue that needs addressed before we move. Does the compressor cycle off, and the reading stay constant? Need to look at the governor, and little line to it. Might need cleaned, adjusted or replaced. If the compressor runs all the time, and you don't get full pressure, most likely you have a serious leak.

I had 02 Horizon with strange gage readings. Before replacing gages I called freightliner tech support. They had me replace a computer module (I cannot remember what it was called) in back of the coach. This solved the problem. It was not the gages. I suggest you call chassis manufacturer tech support and discuss problem with them.

Personally from what you describe I would believe the gauges are correct.
You might want to consider taking it to a good truck shop and have them troubleshoot. They should be quite familiar with air systems.