Why is my Alternator smoking

[Jessej1111]

Hey guys so here is the deal. I went out to start my car this morning but my battery was dead. I pulled up my wife's car to jump it. I hooked up the jumper cables the proper way no backwards crap or anything. I then let it sit for about 5 minutes to charge the battery up in my eclipse.

After about 5 or so minutes I started to notice there was smoke coming from the alternator

I was like wtf is going on here.

So heres the back story my battery light was on last week and it turned out the alternator was bad. I then replaced the alternator with a known good one from a talon I have. The battery light was still on even after that so I was like wtf and started inspecting things and it turns out the alternator choke fuse thing was broken. I replaced that as well. I did run the car after everything was replaced and did not notice any smoke from the alternator.

I have not run the car in about 4 days so I went out this morning to start it and go to the store and it was dead so I was like wtf I must have something draining the battery

and that leads me to attempting to jump it and smoke from the alternator.



my question here is WTF could be wrong that the alternator would smoke.

no there is nothing leaking on the alternator no oil/coolant or anything

The alternator was smoking before I even started the car and got super hot to the touch.

Could this be the ASD relay or the voltage regulator inside the ecu? how can I test that?

 

[sbeck]

Shorted diodes inside the alternator can make it smoke.

 

[Jessej1111]

Shorted diodes inside the alternator can make it smoke.

any idea how they could have shorted? This alternator was working when I drove my talon like 2 or 3 weeks ago.

 

[4CEDinduction]

Yea definitely sounds like a short. It happens, but you can test it to make sure. You need to run a amp draw test with a amp/ohm/volt meter.

 

[Jessej1111]

Yea definitely sounds like a short. It happens, but you can test it to make sure. You need to run a amp draw test with a amp/ohm/volt meter.

Can I do that without my car running because as soon as I hook up the battery the alternator gets hot and starts smoking.

 

[4CEDinduction]

I personally don't know how to test an alternator if it isn't hooked up to a running engine. If it starts smoking once the battery is hooked up to it, I think its safe to say you need a new one.

 

[ChiTownHussla]

When you jumpstart a vehicle, you are only supposed to turn on said car. Not run the car with the cables connected. You said you did it to "charge" the battery, but that is the Alternators job in the first place. IMO you messed up your alternator by running it like that. Anytime you jump a car, you connect cables, turn dead car on, take off cables, and go for a little run down the block to charge it back up. This is what I was taught in school and on the streets. Correct me if I am wrong.

 

[Jessej1111]

I may have explained it wrong. I hooked up my second car like normal to jump the eclipse. I did not run both at the same time. I let the other car charge up the battery for a few minutes and before anything was started on the eclipse the alternator started smoking.

 

[mattasi]

I know you said the alternator is known to be good, but I think it is the alternator. If not the alternator then start following all the wiring from the alternator back to the battery, and look for anything abnormal. But sence the alternator is smoking when you hook up the other cars battery then you know that the power is getting to the alternator threw the wiring, so the wiring is probably fine. I still think alternator. More specific "a short" in the alternators internal wiring.

I suppose it could be a short in the ECM, on the part of the circuit board that controls the alternator, maybe a trace on the board shorted to another one.

So I would take that alternator down to a good shop and have it tested, and then look for other things, hope I helped some. Good Luck

 

[Jessej1111]

Ok so I figured this out.

so long story short.

The alternator in the car WAS good before I installed it in my eclipse. After the install I also ended up replacing other things like my alternator choke. It seems that when I replaced the alternator choke I did not disconnect the battery and by unhooking it and hooking it back up it shorted the alternator internally.

I took the alternator off the car and took it into advanced auto and their machine would not even spin it up because of internal problems.


Thank you all for all of the help.