Chrysler Repair: 03 Minivan: died while idling/ticking sound, battery clamps, volt ohm meter

Question
Recently my oil light would come on at stop light during idle then go off after leaving light. Tonight as i was sitting in the fast food line, light came on and engine started idling rough, rolled my window down and could here a ticking sound,within a few seconds it got louder headlights dimmed and van died, tried to restart but it turned over started up then immediately died...after pushing it out of the fast food line into a nearby parking lot tried to start it again but i get the buzzing ticking noise you get from trying to start with a low battery...checking engine codes vie the on-off trick i get a P 1684 code...battery disconnected within last 50 starts....battery clamps look to have white bluish dust/corrosion around them and i did have to clean the posts last month as the battery died...alternator? short? oil pump??    thanks

Answer
Hi Justin,
The symptoms would appear to point toward a short circuit in the charging system or perhaps elsewhere in the electrical system. Does the ticking sound come from under the hood or from the fuel tank (fuel pump)? Put the key in the run position and find out what is ticking. It could be a relay that is unable to remain closed due to the battery voltage being marginal.  
The headlights dimming when it way dieing suggests beginning the search by looking at the wiring of the battery cables' insulation and the alternator wires. The alternator itself failing is another possibility.
If you have a volt-ohm meter check to see what the battery voltage reads now, and also read the ohms measured between the two disconnected cables with the key in the 'off' and the key in the 'run' positions. In 'off' it should be at least 100 ohms with all the doors closed so that no lights are in the switched 'on' position. In the key 'on' position it will be lower but still non-zero ohms.
Let me know what you learn and we can go on from there.
Roland
Please "rate" my answer, and when you see the 'volunteer of the month' question consider giving me a 'yes'. Thanks. Sorry for the delay in answering your question but I just found it this morning in the question 'pool' to which it had been referred by the other expert.