"Computer Prog" wrote in message
...
This is what my system looks like:

http://www.i2.i-2000.com/~rbartick/wilson.jpg

The lower right side of the picture is the water main from the
house. The left side is the water going to the electronic valves.
I was connected my air line to the removable drain cap seen at
the bottom of the PVC on the right side of the picture. This cap
is before the breaker. I also tried to connect my air line to the
small test port on the upper right side of the picture right below
the Wilson breaker. I didn't try to connect air to the small test
port after the breaker on the left side of the picture because I
was worried that air might flow back towards the valve in the wrong
direction and possibly damage it.

I do not have auto drain valves and there are no other ports I can
connect to. I definitely got the heads to pop last year using the
drain plug but I am not sure what I did. I may have disconnected the
50-ft copper coil that sits on my compressor output. I am going to
try to move the compressor right near the sprinkler valve and run a
short line from the compressor to the sprinkler.

Moving the compressor should help. If you really want to see the
heads "pop", run the water first so the compressor can develop some
pressure in the system. If the water is already gone, maybe your
compressor is inadequate to develope enough volume with high
leakage at the heads.

Bob