Question
I have a raised flower bed that has all of the sprinkler heads installed and ready to irrigate but this control valve has never worked.  It was installed prior to my purchasing my home and I do not know if this area has ever worked.  Currently it is not wired to the control box.  

I have read in my research that the control valve needs to be higher than the highest sprinkler heads it is feeding. I was wondering if the problem might be with the level of the control valve that is controlling this elevated flower bed.  

It is currently about 8 inches from the ground and the highest sprinkler in this line is about 4 feet off the ground.   

I am planning on replacing several leaking control valves.  If I replace this one at 4 feet high do you think it will work?

Answer
Thanks for your question.
The valves can operate (electrically)at any elevation above or below the sprinklers. Now, if you have a backflow preventor/ valve combination. This type of valve needs to be higher than the heads for the backflow preventor to meet "code". The fact it is installed 8" above ground leads me to believe it may be this style of valve.
Have you tried turning the valve on manually? If it work then the problem is between the controller and the valve.
It is possible since the valve/ backflow preventor is not installed to "code". (above the highest head) The pipe was disconnected from valve to satisfy a plumbing inspectors request. You might want to dig up the valve and check the piping.
Good luck.

Matt