[Richard]

Brad,

Glad it's working for you.

Michael helped me figure out the tag sixpack works, and it's pretty interesting. Well at least to a recovering engineer.

If you look at the supply line to the DRIVE sixpack, you will see a solenoid valve and air line leading to the top of the TAG sixpack.
That line will supply pressure to the TAG manifold at whatever the supply pressure is. But the passageway leads straight out the bottom of the manifold and feeds the pressure regulator for the TAG pressure. The output for the pressure regulator then feeds into the manifold outlet where the HCV would normally feed. The vertical passageway for the far right side MUST be drilled all the way through for the outlet pressure to reach both sides of the tag when the travel solenoids are open.

Now it gets a little tricky. When in level mode, air at the supply pressure will reach the tags if the up solenoids are energized. BUT, if the down solenoids do not energize on Micheal's coach if the down button is pressed. The TAG switch to release pressure on the tags must be in the release position for the down solenoids to work. In addition the down switch on the dash causes the solenoid valve on the supply line to close, cutting off supply pressure to the tag manifold.

You'll have to study the picture with this explanation for it to make sense. I hope this helps you in the future with diagnosing problems with this setup.

Mucho gracias to Mr. Day for taking pictures, activating switches, and helping me vet the logic.