Help !! Alternator output stud red hot and melting plastic

[ilium007]

Hi - I am helping my sister and law with her CJ Lancer. She paid for a replacement motor and then paid someone to put it in. It is making a horrendous noise from what I thought was the idler bearing up the top or the power steering pump. I then had a closer look and could see the plastic cap on the output stud of the alternator was melted. I pulled it off and can see that the nut on the stud was basically white it has been getting that hot (see picture).

Does anyone know why this would be happening ? None of the fuseable links are blown and if I start the engine while touching the back of that nut it's getting so hot within about 30s I can't keep touching it. As soon as the engine stops the nut cools down and doesn't get warm when the engine is off.

 

[Joshy_morris]

Re: Help !! Alternator output stud red hot and melting plast

gets like that when the nut is loose, alternators pump out some decent current at times, if thats loose, it will get hot, heat causes resistance, resistance will inturn cause more heat as it tries to pump out more amps, before you know it you have this. commodores are good for it. the peices of shiit.

this also happens to commodore starters, people always think its a battery issue when the car cranks slow then fires, its not its a loose stud doing exactly this.

 

[ilium007]

Re: Help !! Alternator output stud red hot and melting plast

Thanks for the reply. I am at her house and of course I don't have a 12mm spanner here. But... I can't move the connector on the back of the alternator.