Nissan Repair: 95 Nissan Maxima battery drain, nissan maxima, amp meter

Question
I own a 95 Nissan Maxima that seems to have a battery drain.  If my wife does not drive it for 3 or 4 days the battery is dead and I have to either boost it or charge the battery.

The first time it happened we were told to replace the battery, which we did.  Same problem again.
I have had four differant auto repairs places review the car  and all have told me they cannot find anything as far as a drain.  The check engine light is on and I do know it is about time to replace the timing chain.  Is there anything else that I can do and does the timing chain have anything to do with this problem?

Answer
Denis,

If you have a chain and it is not making noise do not change it.  If yours has a timing belt, which I think it does, then change it per the mileage interval in the owners manual.  The check engine light should be checked via Autozone or Checker for free.  Just take your car there.  Also, they can do a check of your electrical system.  A drain that takes four days could be the light in the trunk staying on a number of different things.  You could isolate systems to see if one thing drains the system and that is how you would find it.  You need a amp meter to find which curcuit is drawing power when the car is off.  Also, if you have had any additional equipment installed prior to the drain problem would be a good place to start.