[rheavn]

You Gurus did such a good job of leading me to the pocket doors maybe you can help me with a few issues I'm still having in completing my schematic. 

There is a "T" that comes off the unregulated side of the 12V air pump--this "T" also connects to the 3 gallon air tank in the right rear wheel well with a 3/8" line.  There is another "T" that is unregulated air coming from the 3 gallon air tank in a 1/4" air line.  Both "T"s have 1/4" air lines exiting them and running side by side from the rear of the AquaHot compartment (R-5) and going into the next compartment forward (R-4) in the ceiling wire chase. 

This is where the first problem is encountered.  You can see the two air lines from where they start at the "T"s until they get about half way through the compartment going forward.  At that point you lose sight of the two similar air lines.  Going to the compartment forward you can see the two 1/4" air lines in the wiring chase.  Unfortunately you can't see if they crossed somewhere.  One of the lines continues forward into the next compartment forward where it connects to the slide seal regulator. 

The other air line gets a little more confusing.  In the wire chase of compartment R-4 this 1/4" air line "T"s into a 1/4" air line coming from the rear of the coach.  Now a second "T" in the air line from the rear sends a 1/4" air line back to the water bay on the left side of the coach and connects to the "IN" port of the left side dump valve solenoid.  Following this air line from the rear of the coach forward leads into the next compartment forward (R-3) where it is coiled up & capped off.

The first question is where do you think this mystery air line coming from the rear of the coach originates?  And what is its purpose?  Since the air line that was "T"d into is unregulated, is this where Newell ties the 12V and the main air system together?

Which "T" do you think supplies air directly to the slide seal regulator and why?

Thanks in advance for your ideas!

[Richard]

I am a visually oriented person and I haven't had enough coffee to follow your words. Can you sketch a diagram of what you have Of course it will have holes in it because that is what you are trying to figure out.

Here are a couple of concepts that may help you figure it out:
There has to be a check valve between the 12VDC supply air and the line tying it to the overall supply. Otherwise the 12VDC would try to supply air to the entire coach.
It is my understanding based on my own coach and posts by others that the 12VDC pump supplies air to the potties, slide doors, and slide seals only. (Plus the Bode air door if you have one)
My slide seals have a separate regulator for each one since they run at a very low pressure.
I believe the tank in the rear passenger wheel well is fed by the 12VDC compressor. ( And possibly supply air, see below)

I don't know this for a fact, but you could tie the 12VDC compressor and the house supply at the ping tank, if you put a check valve on the supply line at the tank. Then the unregulated line from the 12VDC pump to the ping tank is a two way line. When the compressor is running it puts air in the tank, when air is needed air flows out of the tank and on through the regulator at the 12VDC compressor. That way, the air pressure to the potties and air doors is always regulated by the regulator at the 12VDC compressor, and it doesn't mattter where it comes from the 12VDC compressor, 120 VAC compressor, or engine compressor.

This is a key point in that the air for the doors and potties has to originate downstream of the regulator at the 12VDC pump. The air for the bladders may or may not originate downstream of that regulator since the bladders have their own regulator.

My pump uses the well switch to turn it on and off.

Last point, the air line for the rear air seal runs just inside the wheel well on the driver side. It's tucked up right by the fender flare. I know this because when the coach sat on the tires at 70 mph, the tire rubbed a hole in that air line.

Thank you for doing this. This is a very important diagram to document the air system logic at the 12VDC pump. There is a lot going on right there.

As usual, I am probably wrong, but one of the gurus will set me straight. :-

   

[rheavn]

"There has to be a check valve between the 12VDC supply air and the line tying it to the overall supply."

The only check valve I have found, so far, is at the "T" coming out of the 3 gallon air tank where the 1/4" air line from one of the "T"s connect.  That is why I believe this "T" supplies the 1/4" air line that splices into the 110 psi air line that comes from the rear of the coach and then is stubbed off.  That way supply air does not go back into the 3 gallon air tank.  Does that make sense???

"Can you sketch a diagram?"

Yes.  I'll post later.

So far I have the toilets, pocket doors and a 3/8" line that disappears up into the floor that are supplied with 60 lbs regulated air from the 12V air pump.  The slide seal regulator and the dump valves, left & right, are supplied with 110 psi unregulated air.  Note that my coach only has one slide seal regulator that feeds air to both slide seals.  Also on my coach the 12V air pump has a pressure switch just like the 110V compressor. "No two Newells are the same"

Clear as mud ey??????? I'll buy you an expresso at Ruidoso

[qcj]

Steve, I have two slide regulators.  One is in a bay and the other is under the bed where there is a trap door with 4 screws.  It is sort of hard to find within the gray carpet and I am probably the only person to remove it since the coach was built. I also have a pressure switch on my 12 volt compressor.

[rheavn]

Chappell,
THANKS ALOT!!!!!  You just put the last piece in the air system puzzle.  When I first got my coach I asked Newell where the regulator for the rear seal was and was told if I didn't have a second regulator in the electrical cord compartment that I only had one that served both seals.  I had one unaccounted for air line that goes to the back of the coach that I'll bet goes to the second regulator under the bed.  I will verify this tomorrow.  

I now know how the 12V air system works and how it interacts with the main air system.  I'm putting together a schematic that I'll post.

[RussWhite]

You'll find it under the bed after removing the access panel .

[rheavn]

Attached is the 12V air system and how it interacts with the main air system.  The 12V air pump only puts out 60 psi.  The main air system puts out 120 psi.

To make things easier start with the main air system having no air pressure.  Follow the air from the 12V air pump and you'll see how it pressurizes both slide seal regulators, both of my toilets, both pockets doors and the 3 gallon air tank in the right wheel well to 60 psi.  Note how the check valve on "T" #3 on the air tank will not allow air to exit into the main supply system.  

Now energize the main air system with 120 psi of air.  The stronger air is supplied from the stubbed off main line and energizes both side dump valve solenoids with 120 psi.  The stronger air can now enter the 3 gallon air tank and boost its pressure to 120 psi.  120 psi air now goes to both slide seal regulators.  The stronger air enters the 12V air pump fourway and tells the pressure switch that there is more than 60 psi so no reason to turn the pump on.  The 120 psi air goes through the 12V air pump regulator & is reduced to 60 psi and supplies both toilets, and both pocket doors with 60 psi air.

I hope this is clear and is useful in understanding an important part of the air system. This has been a fun project & I thank every one for their help.

[Richard]

Way to go Steve !!!!!!