[rheavn]

I have chased an air leak from the back of the coach to the front.  I isolated the leak to a line on the Blue circuit" distribution block under the left front valance.  One by one I have eliminated the following circuits which have no leaks:
110V compressor pressure switch
Genset in/out valve & cylinder
"Supply" dash gauge
3 gallon air tank in R-1

There is only one air line that I now have not positively identified and that is the 1/4" black air line that connects on the upper front of the distribution block.  Of course this is the air line that is leaking.  It is impossible to follow the air lines in front as they disappear as a large group.  I have disconnected lines where I thought it might go & blown air through, but no go.  The air line does not go to the air horn.

I'm out of ideas currently.  Does anyone have any ideas of what runs off 120 psi air pressure in the front of the coach that I have not eliminated?