Chrysler Repair: Engine seems to be spiking high, chrysler sebring, platinum plugs

Question
I have a 2001 Chrysler Sebring LX 2 door, with 95,500 miles.  Last week I had a major tune-up (platinum plugs, wires, rotor cap were all replaced).  I have since noticed that the engine seems to rev for brief spurts, particularly noticeable at lower speeds (25-35) and when I start up from being stopped.  Also, the battery appeared to just "die" - no lights, no dinging when the door was open.  Had the battery jumped - tested the battery, but it was fine.  Could these problems be a result of something that was done during the repair (like something was re-connected properly) or is this a sign the altenator is going bad?  I know the battery was removed and the plugs are at the bottom of the engine, so I'm thinking anything is possible.  Any suggestions are welcome.

Answer
Hi Beth,
The failure of the dinging/lights, momentarily, would make me wonder if the cables are both firmly attached to the battery and also if possibly the connection of the battery cable that is attached to the - post clamp (at its other end, to the engine block) might be loose or corroded. However that also could have been due simply to the switch that senses when the door is opened was sticking in the door shut position for that moment. If you have reason to believe it was more than that (e.g. no headlights, other electricals also stopped working) then:
 begin by removing the clamp for the - post (this is for safety).
Then check the + post clamp to be sure it is tight. Then go to the far end of the - wire to be sure it is attached tightly and cleanly to the point at the rear of the engine. Then lastly reconnect the - post clamp to the battery.
As to the brief spurts, see whether this continues and attempt to tell me more specifically if it a momentary die off/recovery or an actual spurt.
Roland