Alternator wire glowing!!!

[Seouljer]

So I was driving today and smelled something burning under my hood. I quickly pulled over and looked in the engine bay and saw that the wire that attaches to my alternator by a ring terminal was glowing hot. I let the engine cool and then started looking for wires that might have been frayed or cut to cause a ground issue. When I went to grab the ring terminal wire the damn thing was so cooked it broke off. So now I have to get a new ring terminal with is not a big deal. My question is what made the wire get so hot in the first place? Bad alternator? Thanks for any help

 

[ChiTownHussla]

resistance makes heat. or lack of resistance can also make heat.

 

[Colt4G63 also]

I would say a short circut most likely caused that.

FYI: You'll need to replace the wire too.

 

[Seouljer]

The wire is short and goes back into the harness how far do I need to take it back and replace?

 

[Colt4G63 also]

The entire part that was glowing. Glowing tends to burn up insulation, and weaken the copper strands. Typically it will glow along the entire length of the wire, or at least from the power source, to the spot where the wire was shorted to ground.

 

[YZFR1]

I had something similar happen with my brothers car, he had an open dump tube actually touch and short out the alternator wire. Left me stranded on the median

Check the wire with a multi-meter for resistance and voltage, also check the battery for shorts with an ohm meter. But the easiest fix will probably going to be having to run another wire in parallel to the original one. I ran a 4ga alternator wire on my dsm in parallel with the existing wires just to help it push more current. Look for an 80amp fuse on the passenger side. It goes from the battery terminal to the fuse than to the alternator.

 

[xyexz]

By any chance have you moved your battery to the back of the car? Might want to make sure you don't have any cuts in any wires going to the back of the car touching body panels if so.

 

[SlowChild3]

Make sure you remove the loom and check all the other wires in the harness for damage.

 

[Seouljer]

Thanks for all the info!!!! I have an amp kit that I didn't need so im gonna use it to run a new wire and im gonna check the harness to see if I damaged anything.

 

[kchaazz]

^^ Id get the alternator checked as well, just to be sure it was not damaged. I rewired my alternator with 4 awg wire. The wire goes from the alt to the large fuse box on the passenger side of the engine bay, and its not very difficult to remove the old wire and replace. Im attaching a link to a post by another user who has done the rewire:http://www.dsmtuners.com/forums/articles-electrical-wiring/319463-re-wiring-your-alternator-4-awg.html

I did mine differently though. First, I did not crimp my ring terminals on, I soldered them on, and used heat shrink so that the terminals are well covered, for obvious reasons. Also, I unloomed my harness, removed the old alt wire, and put the 4 awg wire inside the harness in place of the old wire, which I recommend.

 

[Seouljer]

Thanks for the link!!! I have 8 ga wire....will that be enough or should I double up? I have enough to run two wires

 

[kchaazz]

It would probably be ok, the factory "twin" wires appeared to be 12 awg to my eyes. You could run two of the 8's, but could probably get enough 4 awg for less than $20.00 at a stereo shop.

 

[Nekid]

Factory is two 8ga wires.

Could be a combination of two contributors. Short/maxed out alt output and heat from manifold pushed it to red hot. In stock configuration, the charge wires run to the loom under the radiator, across, and into the fusebox. If that link did not blow, then you have a dead short somewhere along the path between the alt and fusebox (if it is a short, which I don't think it is because the car was functioning and the link between the charge wires and the battery didn't blow). In stock configuration, the fusebox is between the battery and alt, check the fusebox, if it was hot enough at your alt and was coming from the battery, the plastic on the fusebox should be a molten mess right now.

A stock alternator should not be able to produce enough current to cook those lines though, otherwise they would have to be fused at the terminal to protect against fires. Heat from your manifold is a more likely suspect.

 

[Seouljer]

I got some info from a buddy of mine that it might have been the nut. He told me that if the nut gets loose at the alternator it can cook the wires. Got the new wire hooked up and everything seems to be fine. Need to get a multimeter and see if im getting 12v from the alt to the fuse box

 

[kchaazz]

^^^If youre wanting to check for voltage there because your windows and stuff are only working when the car is running, the problem is that the fuse between the alternator and battery is blown, which of course you will find with the multimeter.

 

[Joe' GSX]

I’m currently having the same issue , what fixed it for you??

 

[Techn0Nut1996]

I’m currently having the same issue , what fixed it for you??

Have you inspected the damaged wires? After reading the original post it definitely sounds like a short somewhere.

 

[Joe' GSX]

Have you inspected the damaged wires? After reading the original post it definitely sounds like a short somewhere.

Yeah They look ok except the ring terminal almost toasted off now , it heats up glowing red everytime I drive

 

[Techn0Nut1996]

Yeah They look ok except the ring terminal almost toasted off now , it heats up glowing red everytime I drive

What about the nut on the alternator, is it tight?

 

[Joe' GSX]

It should be , i will double check As soon as im off of work , it’ll be quite odd that that’ll cause it though

 

[Techn0Nut1996]

It should be , i will double check As soon as im off of work , it’ll be quite odd that that’ll cause it though

I wouldn't think so either but post #14 says that it fixed the issue. Worth a check because it's easy.

 

[brian9397gsx]

I didn't read all of the original posts. But there's 2 reasons for it to be so hot it glows. High resistance which is bad and short to ground. Either way the wire is done now its been to hot and now the copper will be brittle. Run a new wire from the alternator to the fuse box or wherever it terminates on your car and call it a day.

 

[1990TSIAWDTALON]

I agree with brian, run yourself a new power wire and make sure THE GROUNDS ARE GOOD. Resistance is the culprit, in whatever form it takes.
Do "The Big 3" wiring upgrade. New feed of good size, 2-4 ga, from the alternator to the battery fuse. New ground to the block and frame and I run an extra ground to the alternator itself. All big gauge wire.

 

[ist dwa]

It sounds to me like the wire from the fuse block to the alternator is corroded creating a ton of resistance therefore heating up. the fuse isn't blown so it can't be a short to ground the only other logical explanation is poor conductivity.