96 disco only 68,ooo miles, first 2 new altinators went bad in a 3 month period then 2 new batterys in a 3 month period, all on seperate times... any insite?? i did the test light check to see if there was a drain but i didnt see one...
thnks

 

Something is causing the Alternator to max voltage output beyond normal, and your boiling the batteries to death! Get a free test at pep boys, auto zone... where they bring up the rpms and see if the Alt output is high at high/low rpms

First thing that comes to mind is a short in the wiring harness between the battery and alternator, or a closed relay even a bad engine or dash harness. Disconnect the Battery and pull the Alt fuse, unplug the Alt and ohm check for grounds.

Also look to any added accessories, you would be surprised how many people wire un-fused accessories tapping into the main power of the Battery/alt. The easiest place to find these is at the positive terminal of the battery (extra non-factory wires, disconnect and check); then it becomes a pain, in the dash factory stereo & wires? Look around your vehicle for wires which were meant to power some aftermarket accessory which has now become a ground.

What allot of people miss is the wiring harness for the trailer lights, if you have one. These harnesses on most makes are done at the dealer, and are the cause of big problems, to start flip the cover open is it clean and oil free? Then it could still leave a short in the harness I usually disconnect them if I made it that far. If you tow and it fixes the problem it is only a 3 or four foot harness pretty easy to pull apart and fix. The Parts person at the dealer will reluctantly dig though their back room and supply you with any pig tail male and female pins you may need, they have them.

All and all if you not good with the electrical system of a automobile you could make it worse; somethings should be done by a professional, bit of a ego blow but worth the money!