[quote:0b6e35bde3="wynajms"]My car is a 94 Nissan Sentra with 169,000 miles. About 5 months ago the alternator went out (or so I thougt) and I put a new one in. About 3 days later the power wire to the alternator started to burn up. I put a shield on it to keep it from getting hot and that worked until now. The wire has burned as well as the screw the terminal the wire attached to. I have heard this may be because of the ground wire. How do I check it and if that's not the reason it burns the wire, what else could it be?[/quote:0b6e35bde3]
There are really only a few things that will cause a wire to burn up. Being routed too close to the exhaust system can add to the heat the power cable naturally builds up, and eventually burn the cable. Another thing is too much current flow will increase the heat in the cable and can cause it to melt. Your system shows fusable links that should blow if the current gets too high, and since the system is still working, I would say these links have not blown.
So, your current draw may be high, but just under the limits of the fusable links for them to blow. Over time, this heat could cause the wire to burn.
so, to fix your problem you will need to replace the power cable/harness. This will go to your battery, and to what they are calling a body ground on the opposite side of the engine from the battery. This ground is one that I would suspect as having too much resistance causing too much current to flow in that line. Another ground you should check and make sure it is clean and tight, is the negative battery cable where it attaches to the engine. But suspect each and every connection in the harness as a possible problem. If you have a bad connection, and it has a high resistance, the power drawn from the altenator will have to increase to compensate. Your altenator being bad is a very slim chance, but I would think if it was over charging the system, the battery would not like that first.
Good luck and let us know what you find.
Jul 31, 2006 at 8:44 AM
