If it's not the alternator, then what is it?

007_SuperCoupe

Registered User
I found out today that it wasn't my alternator that was bad. Something else caused a spike in the system that melted the cable off the back of the alternator. What else could possibly cause this? Could just corrosion do this? It didn't appear at all to be corroded...just plain black and very brittle. I'm searching for answers, but not really finding any. I've got the battery out and will have it tested, but I don't think that is it. As far as I know, all the grounds check out. I have been through those in the past. (the not so distant past as well) I'm at a loss. I'd like to get it taken care of while it is apart instead of putting a good alternator back on there only to have a short somewhere else that might make it go bad...

Any suggestions are welcome.

Thanks in advance.
 
Here's my experience with this...

I had a similar situation with my alternator cable. The little "ring connector" on the cable would short out on the back of the alternator case and melt the insulation making everything brittle and burnt like you described. It would also cause the "check alternator/battery" idiot light on the dash to come on and the car would stumble and die from lack of current to the battery. I fixed this by putting a heavy guage connector on the cable, and putting a large rubber insulating washer on the "post" on the back of the alternator. That way when the cable was attached it couldn't make contact with the alternator case causing a short.
 
Thanks, Larry. I'll keep that in mind when I put it all back together. Looking at it, it doesn't appear to have grounded out on the case. The stock insulator, although damaged from the heat, appears to still be there. It obviously did heat up significantly at that spot though. Something had to happen for it to heat up in that spot.

I'm leaning towards that particular component of the alternator went bad, then shorted out there. That's my theory at this point anyway.
 
I found out today that it wasn't my alternator that was bad. Something else caused a spike in the system that melted the cable off the back of the alternator. What else could possibly cause this?

Hook your battery cables up the opposite way. That would do it if you tried to start the car like that.
 
Okay, Wiseguy... A better question I guess would be, what would cause this ON MY SC... My battery light would go on, but that was after the damage was done and the connection to the battery was severed. The alternator still puts out 110 amps at 14.8 volts like it's supposed to...just the main terminal on the back was bad.

I'm looking to eliminate other possibilities before stuff starts going back together.
 
If the terminal is even slightly loose or barely corroded it can cause a lot of heat build up just from the very high current going through even a slight resistance----clean the terminal real well --apply a light coat of non conducting electrical grease---yes they do make it--even Lowes and Home Depot carry it. but most important make sure you solder the terminal on not just a crimp...............Dan
 
:eek:could have the pos wire got cut by a pulley or somthing and hitting ground somwhere???? i know i had the same problem and i found out that the poewr steering pully did that

hope it helps out
 
:eek:could have the pos wire got cut by a pulley or somthing and hitting ground somwhere???? i know i had the same problem and i found out that the poewr steering pully did that

hope it helps out

My IC fan did have its negative wire severed from the pulley...I ended up cutting off the bad part when I took it out, so I don't recall if the pos side was worn through or not. My IC fan hadn't worked for literally months before I started having issues...but that still could be it. I'm working on a much better way to wire it up than what I had. I'm actually in the process of making a wiring harness so I can just plug it all in. It will also look much more professional than what I had in there. I'm learning as I go on the wiring. I'm also getting the proper tools to do it, so I don't run into any issues like I have in the past!

Thanks for the suggestions so far. I'm checking everything so I can hopefully have this issue fixed when it all goes back together. I miss my SC...
 
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