I've had this happen on a number of vehicles over the years and its always been the Solenoid on the starter. They go bad and won't engage the actual starter like their suppose to. The Solenoid is the smaller cylinder shaped part on the outside of the starter with the wires going to it. If you need to start the car temperarily you use a hammer or a long bar and hammer to reach and hit the Solenoid casing while someone else turns the key on the vehicle. You can hit it pretty hard if you have to. Usually works.
It will probably be your starter motor Starter is out!
if the battery and battery conections are good, then you need to replace the starter motor
Try and turn the Impreza engine over by hand. The engine could be locked up and not let the starter turn it over.
When the starter motor refuses to turn over or grinds and clicks when turning then you need a new motor or recondition the old one.
Clicking = Dead battery/not enought power to start the car Grinding = Bad starter
The starter solenoid/relay switch is going bad. Eventually, it will just click and not start.
It does fit what happens when the starter is failing.
The starter is located just behind the top end of the engine. I have a '99 king quad. Mine solenoid clicks too. I thought it was a loose wire because sometimes it would turn over but I took it in and was told i need a new stARter. they run about $75.
Starter solenoid. Can be tested by bypassing with a screwdriver. Possible low battery, bad connection at battery and cables or bad starter.
starter, solonoid, ignition, battery. if it clicks when you turn the key then the battery is really dead or its the starter the battery could still be jumped if its the battery.
Have you checked your starter? If it clicks but does not turn over this is probably the issue. If you have a pipe, lug wrench, or retractable baton(my preference), tap the starter housing a few times pretty hard. Tapping the casing may help un-seize(?) your starter gear which is preventing the starter from cranking. The ultimate correction for your problem though would be testing your starter and possibly replacing it. Have you checked your starter? If it clicks but does not turn over this is probably the issue. If you have a pipe, lug wrench, or retractable baton(my preference), tap the starter housing a few times pretty hard. Tapping the casing may help un-seize(?) your starter gear which is preventing the starter from cranking. The ultimate correction for your problem though would be testing your starter and possibly replacing it.
Starter solenoid? Battery not fully charged?