Find a voltmeter to check battery power at the battery and at the pump...should be at 14.5 volts when the Dixie motor is running. Double check that the connections are clean and tight--not corroded. Make sure the wires are not too thin. Skinny wires will not deliver the full power you need. Voltage drop happens--don't try to operate with 11 volts.
Make sure the entire flow is going to the boom nozzles--not to the agitation. You don't have enough gallons per minute to do both. Shut off the agitation when spraying. Spray the gun into the tank and make sure you are getting about 2 gallons per minute.

There is also a chance that the suction line or the suction filter (if you have one) is plugged with debris--or with gunky residue from last year. Make sure there is no suction leak in the intake tube. Make sure pump is fully primed and no air can get into the system.
The literature says it has a filter on the suction intake. Check that.

 

Thanks for the advice. I found the problem, it was my mesh filter was clogged with the funk. I never seen anything quite like this, either my chemicals reacted funny because of being stored overnight, or something else. What I think it was, was that I use Lemon Flavored dish detergent, instead of hand soap. Whatever it was, it created a white gummy substance, similar to dried caulk, but a little softer. I scraped it out, and it would work great for another minute or two, then re clog. I finally drained and cleaned really well, now its fine. I do however, have to replace filter, as I couldn't get the filter to clean entirely.

Thanks again for the help!