2004 astra wiper fluid motor not working

Check to make sure you're getting voltage at the pump. Pull the plug off, put your probes on the -and + terminals, and have someone activate it while you watch. If you see power, then replace the pump. They're easy and under $30. If no voltage, try from the positive terminal to a different ground. If you read power then, you need to trace the ground and see where it is messed up. If still no power reading then you'll have to trace the wiring back. If the fuse is good, ground is good, but no power... might be a broken or chewed wire