I have a '94 discovery with 3.9l engine and just recently the battery has been dieing over night. I took it to auto zone and had them check the battery and alternator and both tested good. I was checking the fuses under the hood out of curiosity and noticed the 100 amp fusible link (i believe this is for the alternator) (plastic) was melted but the the metal link was still intact just looked burned. The engine also started making a winding sound around the same time the battery problem started occurring. Any ideas on what could be causing this and how to test for it would be much appreciated. Thanks

 

You have a major short and or alternator issue.
What was the voltage when tested?
You may have to go thr, pulling one fuse at a time till you find the short.

 

The "tech" at auto zone said the voltage was jumping all over the place but the diodes tested positive. Do you think i should have the alternator tested again, by a professional?

 

Yes test the Alternator again.
A few years ago I had the samething battery not dieing over night but turning over slow,, test at AZ, good. A few days later the Alt light was on bad Alt.

After going a week or so and the battery may need to be replaced also.

 

I've had this as well on my 93 Ranger Rover. It was the alternator. When the engine was off if you put your ear down close the alternator you can hear a really high pitched sound. If so...replace the alternator.

 

Let a pro check the alternator. and I agree with mike about pulling one by one the fuses until you find the short. good luck.



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