[Richard]

I am going to summarize the situation as Adrian has described to me, and then outline the diagnostic steps to figure out what is going on. I am posting here, instead of doing it offline, to potentially help another owner in the future with a similar problem.

Summary. The coach does not automatically raise from a lowered position, or drop from a raised position, when place in travel mode. The coach has plenty of air pressure, 120 psi. The rear behaves normally. Adrian has rebuilt the solenoid valves. It is unclear whether the front solenoid valves are getting a 12V signal or not. The rear travel solenoids are magnetized when in travel mode. The fact that the front will raise in manual and stay up eliminates major air leak as a problem.

Step one. Unbolt front six pack from bulkhead to allow better access.

Step two. Unplug packard connector for travel solenoid. Turn key on, HWH panel in travel mode. Confirm 12V at packard connector. Reconnect when finished. Assuming you have 12V proceed to step 3. If 12V is not present, we have to figure out why.

Step three. Lower coach all the way in the front. Completely exhaust the front air bags. Completely. Do not have any part of your body under the coach while performing this test. Exhaust all air from the air supply system. Turn off all air compressors. Disconnect one of the air lines going into the back of the six pack at the travel solenoid end. Turn the 120 V compressor on. If the height control valve is working, air should flow out of the disconnected air line. The reason for exhausting all air pressure before disconnecting air line is two fold. One, if the manifold still has the push to connect fittings, it will be impossible to get it to release with pressure on it. Two, if the HVC is working and the system is at pressure, you will ruin your underwear when the line comes loose. Assuming air flows out of the tubing, reconnect, and proceed to step four.

Step four. Disconnect one of the air lines leaving the six pack going to either of the air bag tanks. This air line will be at the opposite end than the travel solenoids. With engine running, and coach in travel mode, air should flow out of the six pack. If not there is a blockage in the six pack.