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Discussion Starter #1
I'm looking for some advice about the following situation and pictures.

Someone borrowed my car and when driving back it was smelling really bad (like burning rubber). I followed the smell and under the hood I noticed something connected to the alternator was melting causing a lot of smoke. Now I know that the previous owner had the alternator and battery replaced about one year ago so I'm suspecting incorrect installation...

I'm pretty sure people with knowledge about this part could think of a problem analysis :)

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I am not well versed in electrical systems, but I would start off by taking it to an auto parts shop that can do an alternator test. It looks like there is some excess amperage trying to get through the cable that isn't being allowed.

Maybe try disconnecting that end and doing a good cleaning of both the cable end and the alternator connection. Hit it with a wire brush to get some fresh metal exposed and maybe add some contact grease. There might be some arcing going on if there is a bad connection.

Just a guess. Take it with a grain of salt.
 

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What you're looking at is the alternator ground or negative terminal if you want.

And no you do NOT want to try cleaning that up with a wire brush , etc. That cable is damaged badly. It needs to be replaced, not cleaned.

That is obvious overheating damage. Too much amps. With electricity, the load (amps) is not determined by the alternator but by the demand. In this case, likely a damaged cable that is not conducting as it should - high resistance. Car is still demanding what power it needs so the load demand increases. Cable overheats as the amps goes above what it can handle.

This is also a bit if a guess as it's impossible to say for sure without hands on testing and investigation. Other faults can do this. It's also strange that previous owner had to replace the alternator and battery but nothing else, isn't it? One doesn't usually take out the other so that implies that there's something else going on.
 

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Discussion Starter #4
I took a better look and according to the invoices there was about 2 months between the battery and alternator replacement jobs.
 
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