[Rixson]

So we've had our 90's Newell going on 5 months. I guess.
For nearly 3 months, we were plugged in to 50 amp
Then, we moved to Colorado, also plugged into 50 amp. In both cases, the 110 compressor was coming on and keeping the main supply tank at 60 to 90 pounds, as it should ..... currently moved to a site in Arizona where we're on 30 amp
Everything seems to work except interestingly...the cooktop doesn't, but also th 110 compressor just doesn't seem to be coming on .and the supply is now 0... brakes over 100.  Is it possible that its just not on the main 30 amp leg?  Or could something have happened in our last trip....triggering a no go.  I hear our 12v compressor start on occasion which I presume is keeping brake pressure high.  I've really not had time to do much other investigation.We're here for a couple more weeks, so looking for advice...

[encantotom]

it should still be coming on. i think....ha where in az are you? i am in wittmann.

tom

[Keith Jordan]

12 volt should be for toilet only.

[Rixson]

We are in Cottonwood north if Phoenix .
12v for toilet is what I thought.. So its strange 110 isn't coming on, I thought it ahould be also. ... I'll start looking for a popped breaker or fuse.

[hypoxia]

Is it hardwired or plugged in? An extension cord would answer the question if it's plugged in.

[Rixson]

So I have a pressure control switch.
I know there's no air pressure...
Checking voltmeter neither side has any voltage...
Checked the breaker, it's breaker 11 top ... Same breaker controls the outlets at the couch and the dynette, and they are working...
... 
I suppose it's possible a wire has broken or disconnected somewhere.. 
I'll have to start the coach to get the air pressure up just to push the generator out.. to get to where the wires run.

No fear of rolling we are plenty flat, as well as brake pressure is still over 100.

Mystery thickens.

[Jack Houpe]

Is it possible that its just not on the main 30 amp leg?  Or could something have happened in our last trip....triggering a no go.  I hear our 12v compressor start on occasion which I presume is keeping brake pressure high.  I've really not had time to do much other investigation.We're here for a couple more weeks, so looking for advice...

Yes and more than likely thats your problem its on the wrong leg of your 50 amp adaptor plug. Have you ever been hooked up to 30 amp before? The 12v compressor is only for the pocket doors if you have them, seals on slides if you have them and the toilet, it doesn't have anything to do with the brakes.

[Richard]

Let’s break this down into digestible pieces and trouble shoot before you start disassembling the coach.

The first sanity check is to unplug the coach from the pedestal and crank the generator, not the main engine. If the 110 comp comes on, you do not have a wiring, fuse, or compressor issue. If it doesn’t, then you should start checking those items.

The reason your brake tank pressures remain up is that there is a check valve on both tanks that prevents brake pressure from leaking back and providing Supply Air.

The 12V compressor is plumbed differently on each coach. All of them supply the air powered Microphor.

Now if the generator runs the 110 compressor, then it is time to check your 30 to 50 adaptor as Jim said. The way it is supposed to work is that both legs of the 50 amp are tied together inside the adaptor and all circuits should be powered. However, you may have a home made device, and even a commercial device that only supplies one of the two legs of the 50. Easy way to check is to use the voltmeter on resistance. Check continuity between the hot 30 leg and both 50 amp legs. Google the plug arrangement to understand which leg is which.

And finally, the stove top is 240 volts, as is the high amp electrical element in the Aquahot. Both require 240 volts which is both legs of 50 amp, 180 degrees out of phase. You only have one phase anytime you are on 30, 20, or 15 amp service.

Oh yeah, one more thing. You have a misunderstanding about air brakes. The park brake comes on automatically when tank pressure is below 60 psi. The park brakes are great big springs, completely mechanical. When you release the park brake YELLOW button in the cockpit, you are actually supplying air to counteract the spring. It’s a failsafe design so that you cannot drive the coach without adequate air brake pressure because you cannot release the park brake without at least 60 psig of brake tank pressure. So, NO danger of you rolling away because your 110 compressor isn’t working.

http://www.newellowner.com/newell-air-system/ That will help you, and put you to sleep too.

[Rixson]

Richard and Jack thank you guys for your latest responses to this ... they are right on track with what I was going to do today..
I appreciate the clarification on the brakes. It's funny when you think you know what you know. But then you don't :-( so I appreciate the explanation.... I didn't ? 
I may start with switching the 30/50 adapter...I know it's been repaired at least once... 
Geni only starts if I touch her in the right place outside...so may have to start the coach to get the geni bay open... 
As usual, everyone is so helpful with a bit of humor to boot.  I will go take a look at that link. Because do you have other minor air system issues and maybe that will help as well.
Thanks I will update with findings later today.

[Rixson]

Ok, so after some more diagnoses....
Tried several different thirty to fifty amp adapters, that I had even one that joins in 20 amp alongside....
No cigar... nothing different.
Started rig, got enough air to pop out geni.
Got geni going and confirmed full power profile after switching OFF shoreline to geni power ....by using the 240v cook top with success.... lowered air PSI in supply tank to 40 and that should have activated the 110 compressor at 60 per past observance....no cigar.
Retested for power at the air psi controlled switch and still neither side has any voltage.  ...
Instinct anywhere else in my old coach would have been one of the hidden gfci outlets popped but all the outlets that I am aware of in this coach are working properly.  

I guess my next test is going to be to override the air operated switch with direct power from good outlet...
But first I have to isolate, which side is the hot side.