Hi, I have an '04 Outlander AWD. I was out running errands a couple days ago and the Brake and Battery lights came on together. Now, from googling, I've found that this points at the alternator, but read on. The lights were on for about 10 minutes, then started flashing in unison. Then they both went out. Then came back on. Then out. Repeated multiple times. Had to make several stops, and the car always cranked normally and started fine. On my way home the Antilock light came on, along with the Brake and Battery lights. Then they went out, and haven't gone on since. The Antilock light, however, comes on, but only when I'm moving at least 10-20 miles an hour. Standing still, starting/stopping, no light. Got home, no problem. After googling, it was suggested to run the car and see if the headlights dim. Ran out around midnight, car cranked strong and started. Turned on headlights, bright as usual. Next afternoon went to check it, knew there was a problem as soon as I hit my remote. Nothing happened. Unlocked the car with the key, no interior lights. Tried to start it, TOTALLY dead. Put the battery on a 15 amp smart charger. Charger went to max charge. Took several hours but charger indicated that battery was fully charged. Tried to start the car, started with no problems. Next morning I go to start the car and it's TOTALLY dead again! Could something be sucking that much juice out of the battery overnight? Of course, it could be a bad battery - I'm hoping it is, since it's only 4 months old from Costco, with a 36 month replacement warranty. So, does this sound like a bad battery, or like I said, could a bad alternator (or something else) kill a battery overnight while it's parked? Thanks!

 

Most auto parts shops can run tests on the alternator and battery, free of charge. you only have to remove them and bring them into the store. However, the alternator test doesn't test for everything. I generally take my stuff to Advance Auto...but I'm very sure AutoZone, O'Reilly's, and NAPA test them as well.

I've had an alternator with a faulty voltage regulator, but only after RPMs were above 3k rpm...lower RPMs were fine. When I brought the alternator in for testing, they only ran the alternator less than the equivalent of my engine's 3k RPM.

 

Thanks, ccernst. I'm trying to avoid removing the alt if I don't have to.

 

Check battery connection. Overtime white stuff builds up there and may cause this start up problems. It also could be a loose connection from vibrations. I had this intermittent problem with my other vehicle after I replaced the battery. The posts were a tad smaller than the oem battery. I ended up putting a post spacer to make sure it gets a tight fit.

Also, from another suv forum here are some causes of battery drain:
1. HFL and the A/C compressor clutch relay. And both can be sometimes intermittent. So unplugging one to rule it out is an excellent strategy.
2. newly installed aftermarket eqpts like backup camera, radio head, amp, etc.- connections not properly insulated.
3. Of course like what you've suspected- bad alternator.

Here's a good read I found online-and with a little bit more detailed with the test you've done.
Part 1 -Testing a BAD Alternator, Fast and Easy Test.
This is the EASIEST on car test for testing a BAD ALTERNATOR! If you've been wondering how to test the Alternator on your car... this is the test to do.
It'll help you to diagnose a BAD Alternator in a pinch. It's a fast test and more importantly an effective test to find out if the alternator is in fact bad.
This ON CAR TEST doesn't require any tools, such as a multimeter or anything else. And whether you're driving a Ford, a Chrysler or a Dodge or a Plymouth, a Nissan, a Mitsubishi, a Volkswagen or whatever, this test will work.
Also, you can avoid the most common mistake made when testing an alternator of disconnecting the negative terminal of the Battery while the engine is running. Not to mention that this is a really, really bad way of checking for a bad alternator.

Common Symptoms of a BAD Alternator

Here are the basic symptoms of a BAD Alternator:

1. The vehicle does not start.
2. You know it's not the Starter Motor because if you Jump-Start the vehicle it Starts and Runs but:
   1. A few minutes or seconds after you disconnected the Jumper Cables from your vehicle's Battery, the vehicle dies.
3. Or the vehicle may stay running for a while until you start turning on accessories (like headlights, a/c, wipers, etc.).
4. The Battery light comes on and stays on the whole time the vehicle is running.
5. At dark, when you turn on the headlights, both headlights and dashlights are very dim.

Tests to See if Alternator is BAD or Not

Ok, lets get started..... The test works in this way: You'll be using the vehicle's dome light to diagnose the charging system. You can do this test by yourself or you can have someone helping you.

1. Step 1
   1. Start the vehicle. Either jump-start it or charge the Battery to get it started.
   2. Open the door and leave it open so that the dome light can come on and stay on.
2. Step 2
   1. Disconnect the jumper-cables or whatever it was that you used to start the vehicle.
   2. Go back to the inside of the vehicle and eyeball the dome light.
3. Step 3
   1. If the vehicle stayed running after disconnecting whatever it was that got it going, then notice the dome light's intensity.
   2. Now turn on the headlights and notice the light's intensity once again.
      1. The light should dim a little and then resume its brilliance to the way it was before the headlights were turned on. If this happens the alternator is doing good.
      2. If the light dims and DOES NOT return to its previous intensity and CONTINUES to dim, the alternator is faulty.
4. Step 4
   1. With the vehicle running and with the headlights still on...
   2. Turn on the blower motor on high and notice the light's intensity once again.
      1. The light should dim a little and then resume its brilliance to the way it was before the headlights and the blower motor were turned on. If this happens then the alternator is doing good.
      2. If the light dims and DOES NOT return to its previous intensity and CONTINUES to dim, the alternator is faulty and not charging the Battery or supplying the vehicle's electrical needs.

Interpreting the Results of Alternator Test

Here's an overview of the results from this simple and basic test:
If the alternator is BAD, as you turn on load after load (headlights, blower motor, wipers, turn signals, etc.) then eventually the dome light and the headlights will get very, very dim till the vehicle stalls.
If the alternator is not BAD, then the dome light and the headlights will stay on and brightly lit (after a slight dim as the load normalizes) no matter what you turn on.
It doesn't matter how discharged the Battery is. After the vehicle is started, either by a jump-start or by charging the Battery, this test applies. And it doesn't matter what type of vehicle it is (whether it's a Chevrolet, Hyundai, Buick, Pontiac, Honda, Suzuki, Oldsmobile or whatever), this simple test will get you going.
If you are a Do It Yourself-er, after you have removed the alternator from the vehicle, have the autoparts store (where you're buying your alternator from) test it on their bench tester to eliminate any other potential cause of your NO CHARGING Condition.
For a more in depth look and test of the Alternator, take a look at the second article on TESTING for a BAD ALTERNATOR:

 

Good stuff. I posted over in the 3000 GT forum. I'm having a similar issue in a 1995 3000 GT SL. Problem is, I've had the alternator replaced, and the power is still draining. Lights come on, battery guage starts tanking and the car loses power until it dies. Battery is also new. Any idea about that? Wiring? The a/c flashes on both orange and green.