Bad atlernator or something else?

[nobeconobe]

I was hoping some could shine some light on the potential issue I'm expriening.

Background: car made a "whirling" sound (not a whine; sounded like an electric car almost) the past few days. It happend a few months ago, but went away.

Car has been parked for 4 days. I tried to start it, not stat - completely dead (absolutely nothing; no lights, etc.). The battery is 6 years old. I figured I can just replace the battery my self.

I buy a brand new battery, replace it. Car cranks, but makes a bunch of bad sounding, grinding noises. Some "burnt" smell, too. I stop trying to start it. I wait 2 minutes and start it again, and it starts. All seems fine. No weird noises.

After a minute, the battery/alternator light turns on. Car still runs fine. I shut if off. Wait a few minutes, start it back up. No issues again. 1 minute later, battery/alternator light turns on again.

I shut off car. I come back in an hour thinking it's a bad alternator, and I was gonna try to drive it to the shop (5 miles away) quickly and have it replaced there. But when I try to start it, it's again completely dead. No lights, nothing.

I just want to make sure this behavior is likely the alternator. Can a new battery be completely dead within 1-1.5hrs of installing it and only turning on/off the car for 2-3 times (total run time maybe 10 minutes), if the alternator is bad? I figured I could at least get a crank or unlock the doors.

Thanks for any input!

 

[turblediesel]

Did the "whirling" sound happen while cranking the starter or while running?

Alternator bearings shot and grounding out?

 

[nobeconobe]

whirling/air intake sound while running. No problems then (no battery light).

the grinding sound came while starting it up, but that went away once it go started (and then battery light came on).

 

[turblediesel]

I don't know if the gas KJs have a decoupling clutch (a Liten part) on the alternator pulley like the CRDs do but they fail, initially creating some visible rusty dust. Otherwise I'd suspect the alternator bearings are shot. Can you take the belt off and see if the alternator spins smoothly?

 

[nobeconobe]

Update: Got new battery and alternators, but the issue persists... the alternator is not charging the battery. The car starts and drives fine with a fresh battery.

The shop said they can't figure it out and take it to the dealer as it could be the computer.

Any suggestions? I'm tempted to just go to the dealer, but have no idea what their diagnostic costs are. I'm in the north NJ area.

 

[nobeconobe]

Does anyone have a good shop recommendation 20 miles from Montclair, NJ (free towing only until 20miles... maybe be able to charge the battery and drive a bit more)?

At this point, it's gotta be some sort of fuse, relay, or a bad ECM. I'm looking for a shop that will correctly diagnose the problem and fix it and charge the appropriate price. All the reviews of the dealers in the area don't seem too positive.

EDIT: Can anyone tell me how long it usually takes for the alternator/battery light to come one when there's a problem? For example, after replacing the battery, I had no alternator light for 20 miles, then it turned on. After it turned on, I pulled over and turned it off since I didn't want the car to die.

But I've turned it on/off a couple times since then, all under 60sec, And the alternator light didn't kick on. I haven't driven any longer as I want to preserve the battery for my next tow/shop.

I'm wondering if this is just a delay in reporting, or the car measures the correct voltage/is charging when the light is off... indicating for some reason the car is telling the alternator to stop charging after a while.

 

[DadOSix]

So - something here does not add up.

You can't really tell that the alternator is not charging just by the light.

Need to attach a voltmeter and see what that reading is.

You say above that you replaced the battery and alternator(s)? Maybe just a typo -

The alternator should put out 14.3 - 14.6 or so volts when charging.

---

If you have a voltmeter or access to one, we can walk thru.

Remember, these vehicles are old and crusty - wiring issues galore.

As far as the delay you are wondering on - not in my experience.

Are you comfortable doing your own work?

 

[nobeconobe]

Thanks. So the shop replaced the alternator.. said it wasn't charging. I assumed the shop used the voltmeter.

They replaced the alternator again thinking it's faulty. It still isn't charging. Again, I'm not sure how they tested it. They also told me they "checked the fuses". This was a pep boys, so maybe they don't know what they're talking about. I had to go there in a pinch.

Finally, they said a new battery "might" fix the issue, but they weren't sure what the issue was. I got a new battery and was able to drive 20+ miles before the alternator light turned on. I'm not sure if this means the alternator was working, then failed, or what.

I have turned the car on/off a few times, all short bursts, and the alternator light hasn't turned on.

I can test with a voltmeter on Monday. I've done some more reading and I guess I need to look at the fusible link too.

I'm okay with doing basic work (e.g. I replaced spark plugs myself). I know how to work a voltmeter. Hopefully Monday I can get to the bottom of it.

still looking for decent shop recommendations in the north NJ area.

 

[DadOSix]

Thanks. So the shop replaced the alternator.. said it wasn't charging. I assumed the shop used the voltmeter.

They replaced the alternator again thinking it's faulty. It still isn't charging. Again, I'm not sure how they tested it. They also told me they "checked the fuses". This was a pep boys, so maybe they don't know what they're talking about. I had to go there in a pinch.

Finally, they said a new battery "might" fix the issue, but they weren't sure what the issue was. I got a new battery and was able to drive 20+ miles before the alternator light turned on. I'm not sure if this means the alternator was working, then failed, or what.

I have turned the car on/off a few times, all short bursts, and the alternator light hasn't turned on.

I can test with a voltmeter on Monday. I've done some more reading and I guess I need to look at the fusible link too.

I'm okay with doing basic work (e.g. I replaced spark plugs myself). I know how to work a voltmeter. Hopefully Monday I can get to the bottom of it.

still looking for decent shop recommendations in the north NJ area.

Ok. Understand better now.

So, yeah, a voltmeter will help decide where the problem lies.

Across the battery, fully charged, you should read 12.6-8 ish. With the jeep off.

Engine running, same hookup, should read 14.5 ish as above.

If reading is same as not running, think fusible link or bad ground or bad alternator.

Alternator stud (red wire) to ground, jeep running, should show charging - 14.5 ish.

 

[nobeconobe]

Thanks. I'll try to see if I can figure this out Monday! Will update this thread.

 

[Billwill]

What year/model is your Jeep?
CRDs have the alternator pulley with a built-in clutch that smooths out the effective start-stop action of the rotating engine...this pulley can fail. Early pulleys were "dry" inside and tended to fail sooner than newer pulleys which are filled with grease.

My 2002 Export CRD still has its original pulley....probably jinxed myself now by mentioning this!

The way alternators vary their charge rate to the battery varies between CRDs and Gassers and between models years hence why year/model information is critical!

 

[nobeconobe]

Sorry for not specifying... 2010 Jeep Liberty, Renegade.

 

[Jimmyjimmyjimmy]

Noise and burning smell could be belt tensioner. 65 dollar part and easy to repair. Needs 15mm socket. As for charging 2 bad alternators in a row not impossible but unlikely. When its running can u see if any cables or wires are hot to the touch? Anything look melted? Could be hidden corrosion somewhere.

 

[Jimmyjimmyjimmy]

Noise and burning smell could be belt tensioner. 65 dollar part and easy to repair. Needs 15mm socket. As for charging 2 bad alternators in a row not impossible but unlikely. When its running can u see if any cables or wires are hot to the touch? Anything look melted? Could be hidden corrosion somewhere.

I've let it idle with new battery and alternator for 20 min to see what happens. Years ago i had a rebuilt alternator from a big chain store take 15 or 20 miles to start to quiet down and charge consistently without warning light flickering

 

[nohitter64]

Does the grinding still occur at startup? I was thinking starter...would a bad starter or short in the starter trip the charging light?

 

[nobeconobe]

No, the car sounds completely fine now when it runs off battery.

The grinding/smell sound only came on the first crank upon turning on the car with new battery. Second time it was fine.

This is why I thought alternator was "blown" and got a new one. But new one (and replacement) doesn't charge (will confirm with voltmeter Monday).

but no weird sounds at all.

 

[nobeconobe]

Hi all,

I measured voltage at battery terminal.. started off in low 12s, let the car run, no difference in voltage. Car shut off. Battery drained.

Can someone help me check the fusible link? I'm trying to find a guide right now.

 

[DadOSix]

with the meter leads on the terminal stud on the alternator, red, and the black clipped to the block or alternator bracket or similar - you should read 13.8 - 14.6

Anything else says the alternator is bad.

I don't like to measure stud to the negative on the battery because if the number is low, I still cant tell if it is in the cabling, etc.

If I get good numbers at the alternator, I start to work backwards toward the battery itself.

 

[nobeconobe]

with the meter leads on the terminal stud on the alternator, red, and the black clipped to the block or alternator bracket or similar - you should read 13.8 - 14.6

Anything else says the alternator is bad.

I don't like to measure stud to the negative on the battery because if the number is low, I still cant tell if it is in the cabling, etc.

If I get good numbers at the alternator, I start to work backwards toward the battery itself.

Thanks. Can you be a bit more specific for me? I'll be back at the car tomorrow morning.

This tests the actual alternator, right? I put one lead of my meter on the alternator terminal with the bolt/nut (e.g. the "top" connection to the alternator), and the other lead to the engine block (or even the negative terminal of the battery?), and I should be able to get a reading 13+V read from the alternator, right? If I don't, is that certainly a bad alternator, or could it still be a ECM/computer issue?

Here's what I have tested:

1. With the car off, battery measured 11.5V (it was drained). With the car started, the voltage did not change, and continually dropped until the battery died. This tells me the alternator is not charging the battery.

2. I disconnected the battery. I touched meter leads to the top bolt/cable of the alternator, and the other end of my lead to the positive terminal of the battery. I'm not sure what what I was measuring, but I was able to get a resistance reading. It was kind of all over the place, but touching them did change my meter reading - but sometimes the resistence reading read 0. If there's a specific way to test, please let me know. I can do it tomorrow.

I glanced at the fuse box, and all the fuses "visually" looked okay.

Apologies for not knowing the right terms/methods here. I really appreciate all of your help.

Again, if anyone has a shop recommendation near Montclair, NJ, please let me know.

 

[Sevenmilesout]

Hiya from France,

I presume you have a 3.7.
This particular post was interesting & after a little searching, I found this. It may be worth a good read in order to solve the problem.

2012 Jeep Liberty Limited 3.7L Not charging new batt/alternator HELP

2012 Jeep Liberty Limited 3.7L Not charging new batt/alternator HELP

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