What would keep drawing down the battery? on 1996 Mercury Sable

We have replaced the battery,mega fuse and the constant control relay module. We want to remove the alternator to have it tested. Tests so far show no problems however the car keeps dying and the battery light keeps coming on and the battery keeps drawing down.

by in Portland, OR on August 05, 2014
2 answers 4 comments
ANSWER by on August 05, 2014
If the battery light keeps coming on, there is an issue in the charging system.
COMMENT by on August 05, 2014
What might that issue be? Where should we look?
ANSWER by on August 05, 2014
More than likely the alternator is the cause. If this is a problem when the vehicle is not running, you have a parasitic draw. Something is staying on when the vehicle is shut off.
COMMENT by on August 05, 2014
We have had the alternator tested and it tests ok. We are trying to remove it from the vehicle to have it checked,however can not figure out how to loosen the tensioner on the serpentine belt. Can you help? We can not figure out what is "on" when the car is "off" any ideas there?
COMMENT by on August 05, 2014
No I don't know....usually the hood light is a culprit. It stays on when the hood is shut....you will know if you open the hood and the plastic cover is almost melting hot. Otherwise, it could be almost anything even a loose wire arcing to a metal surface. here is the tensioner location: http://www.hotspotoutdoors.com/forum/ubbthreads.php/topics/1495633/1996_Mercury_Sable_Serpentine_ Just scroll down.
COMMENT by on August 06, 2014
Thanks for all the help!!