stick a bucket of water in the tank and test everything out all ways around. try the same wand with different hoses, try it with your hand tool or any other wands you have. just see if it all appears to run right except the wand.
If it's only the wand, first thing to do is undo the jets and check for any blockages or accumulated crud that gets in there (always a good idea to try really hard to use a clean, crud-free bucket to fill the machine and don't let any bits get in there). stick the jets back on and see if it's any different.
If it's a pump problem you might not spot it with a hand tool, less flow so more time to back up pressure... less difference in performance.
How old is the wand? (jets could be worn, esp. if using chems in-tank) How old is the pump?
Wands generally don't get anywhere near as wet at the edges... has it not always been like that? just a thought
