What type of starter was installed and is the symptom the EXACT same as it was before the starter was installed... I'm not talking similar, I'm talking EXACT same? Crappy aftermarket remanufactured starters can be bad and not work a single time fresh out of the box, new paint and all. If the symptom changed at all, and it is actually clicking as you say, I would lean towards the starter solenoid (you buy a starter solenoid and get the starter motor for free... they come attached if you don't get my joke).
2005 Jeep Grand Cherokee - Gone but not forgotten!