Expert: Roland Finston - 12/30/2011

Question
I just bought a 1993 Chrysler New Yorker 5th Ave. and it has the 3.8 liter v-6 engine, 83k miles.  I just replaced an Interstate battery because I thought it would hold a charge.  The new battery is not dead yet but is getting weak.  I'm not sure why. There are no interior or other features turned on.  Last night as I walked by the car I noticed that the "information center" was running a diagnostic check on the car (note - no one had been in the car in hours).  It continues to run this check periodically as the car sits.  Could this be the cause of my battery drain?  What would be causing this?

Answer
Hi Eric,
Is this the old C-body or the new LH-body New Yorker? Both were available in '93 I believe.
I would try disconnecting the plug for the message center and then see what the ignition off draw is. Put an ammeter between the - post clamp and the - post of the battery and verify that the draw is less than 50 milliamps after waiting for about half an hour to let time out circuits do so. Then measure again with the message center plugged in and doing it 'thing'. Try pressing on the buttons of the center to get it to stop doing its self-test. Once I know which body this is I can possibly determine what initiates the self test and then you can try that to see if it is a matter of a button being depressed contiunously or some other cause. But if the deleting of it from the circuit reduces the off-draw to an acceptable level that should end the problem for now.
Roland
PS I am in a tight race for 'volunteer of the month' and would appreciate your rating my answer.