Dealership is often the lowest-cost choice. You didn't say what the symptom was with the old alternator but if it was the same as with the new one, you're already out the cost of the misdiagnosis. Start by measuring the voltages on the two smaller wires on the back of the alternator while the engine is running.
I don't know what to tell you to expect for one of the voltages. All Chrysler charging systems used to be so extremely easy to diagnose from the early '70s up to around 1999 or 2000. I was just looking at a 2006 service manual and they show a major change in the wiring diagram that I had heard about, but they're still describing the circuit operation the same as the older vehicles used. One of the smaller terminals should have something between 0 and 12 volts with the engine running. 4 - 9 volts is typical. The other wire used to have full battery voltage, but now it is shown as being grounded. You will find either 0 or 12 volts. Holler back with those readings.
If the Engine Computer is unable to monitor the needs of the electrical system, it will default to running the alternator at 25 percent of its maximum output. That could explain why the warning light is on but there are no apparent problems. The battery could be over-charging slightly or be running down very slowly.
Friday, November 30th, 2012 AT 5:04 AM