[Richard]

Carthan,

This is my opinion so take it as so. But I think my comments are reasonably accurate. The bulk of the experience on this forum is with 2004 and earlier coaches. After that Newell made changes by going to multiplex systems, and using slightly different components in the air system. There are a handful of gurus with hands on experience with your vintage.

That being said, and keeping in mind that no two Newells are alike, it will be most helpful going forward to take pictures of the area or problem of interest so that we can see what you see. Otherwise we are commenting based on what we have seen, which may not be what you have. That’s kind of the neg side of the situation, the positive side is that Newell was a builder who used a slow progression of evolution in their systems, so it is fairly straightforward to trace the DNA back to something we recognize.

Let me illustrate. As late as 2004 Newell was equipping the coaches with one 120V aux compressor and one 12V aux compressor. There is a specific pneumatic piping setup that works with that setup. That combo uses the well pump switches of which we mention to control the on off of both compressors. By 2007, Newell had switched to a dual 120V compressor setup all driven by the Valid electronics. You are somewhere in between, and I personally do not have a clue as to your setup.

So let’s start by posting pictures of you air comp setup.

A SWAG is that someone used a pilot operated valve on the air compressor drain/pressure release instead of a direct acting valve. That valve requires air pressure and an electrical signal to close it. Without any pressure, it doesn’t close and the compressor output just dumps to atmosphere. This is just a WAG based on previous experience.