2003 Aerio SX AWD starting problem

Hey guys I finally had a chance to do some tests on the car. With the leads on both terminals, I cranked the car, the voltage dropped to around 10.68. Right after starting it registered 13.6, but I will drive it for a bit until it starts to test again.

Edit: Just drove it for about an hour, about 15min freeway at 60-70, then 45min highway at 40-50. When I returned home, I tested it with the engine running, showed 11.94. So I think the battery is toast. When driving, the dash lights flickered a lot, and when I was almost home, the dash cluster went dark.

With the battery voltage being low after the driving, the most likely problem is with the alternator rather than the battery. You should use a battery charger to recharge the battery. After several hours of charging you should see a voltage around 12.6 volts or more. That would be a good sign for the battery condition anyways. Make sure the alternator belt is good and snug tight and the battery connections are cleaned. Have a load test done on the charging system. It will show you what is going on and if the battery is weak. You most likely are going to need a new alternator if those other things I mentioned are okay. You should normally see a little over 14 volts on the battery while the engine is running around 1,500 RPM with a good running alternator.

As far as the loose ground lead, try to find where it came from and reconnect it. Loose ground connections can cause strange problem to happen depending on what they are tied to. I doubt it is causing your starting problem issue and it certainly isnā€™t causing the charging problem.

Thanks for the input! Would the car still show over 14v running with a good alternator but a bad battery? If not Iā€™ll probably replace both, as the last time I had it tested the autozone person said it was at end of life.

If the alternator is okay, battery connections are good, and belt is tight you most likely should see around 14 volts on the battery while the engine is running and just the battery is weak. It appears you already have a known issue with the battery and I suspect the alternator has a problem also. Have a load test done to verify the condition of the alternator. You need to know if it can handle a full output load and I suspect it canā€™t.

Should I try to disconnect the positive terminal while the engine is running to see if it dies or not? That should tell if if the alternator is bad right? I am worried about the electronics though

No! Youā€™ve done all you can do with your voltmeter. Youā€™re just about to fry something. Do what Cougar said and have a shop run a load test on the alternator.

Can they run the load test without taking it out?

Yes

Hey guys, I havenā€™t had a chance to get the alt tested. I did buy a new battery, and just put it in. The car still doesnā€™t start. A bad alt doesnā€™t affect a good battery from starting the car correct? It still jumps fine so Iā€™m kind of stumped. Iā€™m thinking it might be the starter now.

Solved! Me and my mechanic friend were looking around the engine bay, and I mentioned that the ground wire was ripped off. He said lets connect it and see what happens.

That fixed everything! With it not connected the car would click and not start even with the new battery. With it connected it started every time. While running, it reads 13.6v disconnected, 13.9 while connected. My buddy traced it and says its a body ground wire and pretty important.

Thank you for all the diagnostic help!

Proper grounding to the engine and the chassis is very important. Thanks for the update.

Iā€™m having the same issue with my Aerio sx

For no cranks first thing to do is to use a battery post tool to clean the battery posts and connectors. If that doesnā€™t fix it, and thereā€™s no obvious corroded wires or missing ground strap connections, next step is to measure the voltages at the starter motor, terminal to SM case, during attempted cranking.

Run a ground wire from a good ground from your transmission to the negative cable of your battery.
Your starter is connected to the body of the transmission which is its ground. If it starts, look at your negative battery cable attached to the transmission, It most likely is loose in side its connector and you might even be able just to pull it out. Problem solved,
Symptons, low crank aka not enough power, dash lites blinking, click at starter. You are very welcome.

I find it rude that someone is looking for answers then tells you that they found a loose wire and it fixed the problem, understanding that they are novice. It is the ground wire from the battery attached to the transmission, since it rocks back and forth the way it is designed and no flexibility it eventually becomes loose in it retainer of the connector hidden by the plastic around it.

The starter ground is the transmission which is attached to the negative battery cable.

Why is that rude ? Just because someone needs help and then finds the problem and that annoys you. Also the person returned and said the problem was solved which very few posters do.

I guess we are supposed to say Welcome , so maybe you will have useable advice and on current problems in the future.

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Sorry about being late just got the car, and it had that problem so I thought to share my bad

The way I was trained, complaint, cause and correction then verify the repair, a wire hanging down and disconnect is a wire hanging down and disconnected. But hey, I will stay off this post.

No, @Hurbild_162307, you didnā€™t do anything wrong by posting. We appreciate your coming by.

@db4690 I think we can all agree by now that the party has been going on so long that nobodyā€™s really late anymore.