Ravencrave

Hi guys, I think this is my 2nd or 3rd alternator on my '01 ES300 and have had it for 4 years now. It is putting out a great charge but the connection that goes to the battery is too hot. Last year around this time I noticed that the plastic bonnet covering the connection has burnt to a crisp. I noticed the connection was loose so I tightened up and put electrical tape around the crispy bonnet and continued. Being out of town several hundred miles from home this was all I could do for now. After a while the tape also singed up so I put new tape on it. Now the wire completely snapped off from the crimped connector and wire around it is burnt as well as the connector just about disintegrated. I put on a new connector, cleaned the stud coming out of the alt. the best I could from rust and tightened the best I could without stripping out the nuts. Ran the car from about 5 minutes then shut down . Connection is still hot to the touch. I no longer have a bonnet to insulate the connection so are there any ideas as to what to use to replace it? Could it be an alternator issue or a hot to ground problem? Responses will be appreciated.

Chuckinnj

Make sure all electrical connections are CLEAN...... Not cleaned "good enough" or "as good as I could get it."
Dirty or corroded electrical connections of any kind will create a high resistance connection that will heat up and cause damage or worse yet a fire.
Take a file & wire brush and make sure the alternator post and lug are "super/shiney cleaned up" so there is NO rust or corrosion THEN install it on the lug and tighten the up the connection. Once it is nice and snug take a Q-tip and apply a light coating of dielectric grease on the connection, this will stop any oxidation and help maintain a good connection.
TIP! Buy a tube of dielectric grease and keep it handy for installing light bulbs, spark plug boots, batteries, etc.

Ravencrave

Thank you Chuck! Unfortunately, I'll just have to get a new Alt. since the post is so bad, anymore wire brushing it will diminish to the point that the nuts will just slide in without screwing them in. I just wonder what could have caused that post to rust in such a short amount of time.

Chuckinnj

That is why I suggest a light coating of dielectric grease......... To stop the corrosion.
BTW! Before you buy a new alternator try running a next smaller sized die (SAE or Metric) and cut new threads.... Then run a new nut on the connection post with a lock washer. Of course a new alternator is the best way to go, but if you are on a low budget the thread cutting suggestion will work.

Ravencrave

Thank you! I'll give that a shot.

Ravencrave

Well that didn't go so well and the insulator was in such bad shape, I ended up getting a new alternator and went to a junk yard to find a new connector cover. All is good now.

Chuckinnj

Yeah once that connection gets hot and corrodes all hope is gone.
TIP! Check this "new" alternator post on a weekly basis for at least the first month to make sure it is not getting hot and creating another failure.