Electrical issue, not battery, not alternator

[Erroniously_Spelt]

2015 mitsubishi mirage
First, I know you'll say it sounds like the alternator, I know.

The other day, after dropping off the kids, I was headed home. My radio shut off and random lights popped on, on the dash.

I took it immediately to autozone, battery tested fine, but wasn't charging. So great, alternator, right? Took it out and tested it. 3x tested fine.
Battery was 12.3 volts while running. Should be 14.6. Same at alternator.

I thought I fixed it by cleaning all the connections from the battery to the alternator, wire brush, reconnected everything. I drive it 135 miles on the freeway, no issues. Drive it back, no issues.

Check voltage again, 14.6 while running. Great, no problem.

Next day, took the kids to school, same issue. Radio goes off, random lights pop on. Everything starts dying, battery dies.

Get a charge on the battery, limp home. Battery testing at 11.8 - 12.3 while running.

I'm of the belief that they only issue is now a ground fault. I've inspected everything I can reach, no corrosion, all good connections.

What's my next steps?

[dspace9]

Not sure. Get a second opinion. Take it to a really good mechanic.

I have owned my Mirage almost 6 years, and since new. Still pretty good car and electrically pretty good. One minor thing is my dash light goes dim but only partly.

Like on the right hand side of the middle console area, where the round hvac knobs are, and the horizontal thing that controls the airflow. The whole thing goes 80% dimmer, then you tap it, and it comes back to life. I dunno.

Good luck, and let us all know what happens

[foama]

Of course it sounds like an alternater fault, but...

These cars have regenerative braking feature, whereby the alternator charges the battery under certain conditions such as braking or engine running with foot off gas, regardless of the momentary actual need for charging. This happens by means of the ECU controlling the alternator.


Therefore, aside from the alternator or its built-in regulator acting up, it could be an issue of a certain connector or certain connectors within the same area being corroded. There have been several such cases plus a recall, and it would certainly be worthwhile to have a very good and very close look! Looking costs nothing except maybe half an hour's time. Firstly, make sure to read the entire threads below before starting examination!


See:

https://mirageforum.com/forum/showth...its-corrosion)

and see:

https://mirageforum.com/forum/showth...orrosion-issue

and see:

https://mirageforum.com/forum/showth...IX-relocate-it

[Eggman]

2015 mitsubishi mirage
First, I know you'll say it sounds like the alternator, I know.

The other day, after dropping off the kids, I was headed home. My radio shut off and random lights popped on, on the dash.

I took it immediately to autozone, battery tested fine, but wasn't charging. So great, alternator, right? Took it out and tested it. 3x tested fine.
Battery was 12.3 volts while running. Should be 14.6. Same at alternator.

I thought I fixed it by cleaning all the connections from the battery to the alternator, wire brush, reconnected everything. I drive it 135 miles on the freeway, no issues. Drive it back, no issues.

Check voltage again, 14.6 while running. Great, no problem.

Next day, took the kids to school, same issue. Radio goes off, random lights pop on. Everything starts dying, battery dies.

Get a charge on the battery, limp home. Battery testing at 11.8 - 12.3 while running.

I'm of the belief that they only issue is now a ground fault. I've inspected everything I can reach, no corrosion, all good connections.

What's my next steps?

Hello Erroniously_Spelt and welcome to the forum.

That's an interesting problem. We don't have many reports of charging failures. I don't think there are any examples here on the forum I can point to for guidance.

Since charging is handled by the alternator, it sure sounds like an alternator problem. And since the alternator is controlled by the ECU (as foama has mentioned) that has to be taken into consideration.

What other little details are part of this? Have you modified your Mirage at all? Do you run with anything plugged in to your OBD-II connector? We've had a report of problems caused by an insurance company's premium-discounting spying device causing malfunctions. Not saying it's part of your problem, but little changes from factory can bring big headaches.

Also, I'm not sure the North American market got regenerative braking...

Any chance you could post a Youtube video of the symptoms? If you need help posting, let us know.

[klroger]

Didn't Fummins have an issue with one of his & found a broken wire in a connector under the hood? I don't really know how to use the search, but I'm sure someone can find it (unless I'm delusional again)...

[Erroniously_Spelt]

Of course it sounds like an alternater fault, but...

These cars have regenerative braking feature, whereby the alternator charges the battery under certain conditions such as braking or engine running with foot off gas, regardless of the momentary actual need for charging. This happens by means of the ECU controlling the alternator.


Therefore, aside from the alternator or its built-in regulator acting up, it could be an issue of a certain connector or certain connectors within the same area being corroded. There have been several such cases plus a recall, and it would certainly be worthwhile to have a very good and very close look! Looking costs nothing except maybe half an hour's time. Firstly, make sure to read the entire threads below before starting examination!


See:

https://mirageforum.com/forum/showth...its-corrosion)

and see:

https://mirageforum.com/forum/showth...orrosion-issue

and see:

https://mirageforum.com/forum/showth...IX-relocate-it

Great info!

Seems like I need to get the ecm flashed, and check all connections under the carpet. I'll check recalls on this car.

It's been very wet here for several months. I'll try to report my findings.

[Erroniously_Spelt]

Hello Erroniously_Spelt and welcome to the forum.

That's an interesting problem. We don't have many reports of charging failures. I don't think there are any examples here on the forum I can point to for guidance.

Since charging is handled by the alternator, it sure sounds like an alternator problem. And since the alternator is controlled by the ECU (as foama has mentioned) that has to be taken into consideration.

What other little details are part of this? Have you modified your Mirage at all? Do you run with anything plugged in to your OBD-II connector? We've had a report of problems caused by an insurance company's premium-discounting spying device causing malfunctions. Not saying it's part of your problem, but little changes from factory can bring big headaches.

Also, I'm not sure the North American market got regenerative braking...

Any chance you could post a Youtube video of the symptoms? If you need help posting, let us know.

What other little details are part of this?
Bought it with 26 k miles
Have you modified your Mirage at all? No
Do you run with anything plugged in to your OBD-II connector? No
We've had a report of problems caused by an insurance company's premium-discounting spying device causing malfunctions. I don't use those because I drive waaaay too much last year was 54,000 miles.
Not saying it's part of your problem, but little changes from factory can bring big headaches. True, true.

[Eggman]

Didn't Fummins have an issue with one of his & found a broken wire in a connector under the hood? I don't really know how to use the search, but I'm sure someone can find it (unless I'm delusional again)...

You're right!

Battery Light On

Good catch. I forgot all about that. Thanks for speaking up.

Hey Erroniously_Spelt please let us know what you find.

Depending on the outcome of this, I probably ought to merge this thread with that other one.

[Erroniously_Spelt]

Hello Erroniously_Spelt and welcome to the forum.

That's an interesting problem. We don't have many reports of charging failures. I don't think there are any examples here on the forum I can point to for guidance.

Since charging is handled by the alternator, it sure sounds like an alternator problem. And since the alternator is controlled by the ECU (as foama has mentioned) that has to be taken into consideration.

What other little details are part of this? Have you modified your Mirage at all? Do you run with anything plugged in to your OBD-II connector? We've had a report of problems caused by an insurance company's premium-discounting spying device causing malfunctions. Not saying it's part of your problem, but little changes from factory can bring big headaches.

Also, I'm not sure the North American market got regenerative braking...

Any chance you could post a Youtube video of the symptoms? If you need help posting, let us know.

You're right!

Battery Light On

Good catch. I forgot all about that. Thanks for speaking up.

Hey Erroniously_Spelt please let us know what you find.

Depending on the outcome of this, I probably ought to merge this thread with that other one.

Yeah, this looks like a clusterbomb of badness. I'll check all this, too.... Grr...

[foama]

Of course it sounds like an alternater fault, but...

These cars have regenerative braking feature, whereby the alternator charges the battery under certain conditions such as braking or engine running with foot off gas, regardless of the momentary actual need for charging. This happens by means of the ECU controlling the alternator.


Therefore, aside from the alternator or its built-in regulator acting up, it could be an issue of a certain connector or certain connectors within the same area being corroded. There have been several such cases plus a recall, and it would certainly be worthwhile to have a very good and very close look! Looking costs nothing except maybe half an hour's time. Firstly, make sure to read the entire threads below before starting examination!


See:

https://mirageforum.com/forum/showth...its-corrosion)

and see:

https://mirageforum.com/forum/showth...orrosion-issue

and see:

https://mirageforum.com/forum/showth...IX-relocate-it

PS:

1.) All have regen braking (charging) feature!

2.) The bespoke connectors are electrically located between ECU/ECM and alternator. Physically they are near and slightly above the drivers left ankle. Some of the wires of the connectors have overlaying OBD signals in them. Something wrong within OBD signal transport and the car does WTF it wants and acts up like crazy.

3.) As Fummins and others found out, and as described in the three threads listed, all sorts of random lights come on when there is corrosion within those connectors, and you already said random lights come on in your first post.

4.) The corrosion on a troubled connector is often the actual contact between pin and wire. This may be very difficult to recognize. If you have little experience with electronics, use a strong magnifying glass during examination and take your time. Traces of corrosion are often a greenish substance, providing copper (=wire) is involved. Corrosion between pins looks a bit like rust or dirt, and is often hardly visible. That is what I would look at first, and it costs nothing except a little time.

Good luck!