# BATTERY LIGHT



## Ray Morley (May 10, 2021)

2011 Cruze 1.8 with only 49 thousand KM on it.

The BATT light will come on while driving and it comes on with no predictable pattern to it.

We changed the Alternator and Serpentine Belt and also the Battery,

All the Grounds were checked and cleaned. 

All the Fuses and Relays have been checked.

We swapped the Voltage Sensor from another vehicle.

One thing we did notice is if the light comes on if you pull over and shut the car off and restart it the light will go out.

This car does not have the Voltage display option on the message center.

Any ideas? Could it be an issue with the connectors under the Engine Bay Fuse Box?

Is it possible to 'disconnect' the RVC system and run the Alternator at straight voltage and see what happens?


----------



## Thebigzeus (Dec 2, 2018)

Did you actually replace the ground or just clean it?









Special Coverage #14311: Negative Battery Cable


Just got notified of another special coverage. I don't have the details yet but it's to resolve the loose Negative Battery Cable some people are experiencing. We have had many members report problems with this cable and its connections. I'll post more information when I receive it. #14311...




www.cruzetalk.com


----------



## Ray Morley (May 10, 2021)

I replaced the Ground Wire that runs thru the Voltage Sensor but not the other smaller Wire that is also connected to the Negative Post. Will this smaller Wire cause this issue?


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> We swapped the Voltage Sensor from another vehicle.


I'm pretty sure you mean the amp sensor. If so just be aware it is polarity sensitive, if you have it backward it will mess up the system in short order.


Ray Morley said:


> Is it possible to 'disconnect' the RVC system and run the Alternator at straight voltage and see what happens?


The short answer is yes. However, simply turning on the high beams will do basically the same. 

You really need to give us numbers. The voltage the PCM is seeing can be got from a live data scan. And a voltage meter should be used to check your battery, alternator, and ground continuities. The guessing is over, now we need to find the problem.


----------



## Ray Morley (May 10, 2021)

Yes Johnny you are correct. Turning on the High Beams would demand more power output.

"I'm pretty sure you mean the amp sensor. If so just be aware it is polarity sensitive, if you have it backward it will mess up the system in short order."

The sensor I am talking about is the Oval sensor that is directly connected to the Neg Battery Cable. How would you get it backwards. The connector only fits in one way and the unit snaps into the lock only one way.


----------



## Ray Morley (May 10, 2021)

Further to my question:

The Negative Battery Connector has a large wire that runs thru the Voltage Sensor and then attaches to the frame. The Connector also has the smaller wire the goes down and under the Fuse Box. Where does this smaller wire go to and why? If the smaller ground wire signal ends up in the computer for voltage sensing and it is either broken or has a bad connection then will the RVC not get the proper information? This in turn not allowing the Voltage Regulator to do it's job properly?

Could this smaller wire be causing my Batt light and charging issues?


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> The sensor I am talking about is the Oval sensor that is directly connected to the Neg Battery Cable. How would you get it backwards. The connector only fits in one way and the unit snaps into the lock only one way.


Well, the sensor should be round, not oval. And it is a current sensor, and it isn't directly connected to the negative cable. The negative battery cable should run through it. You might be fairly amazed at what people can mess up. Anyway, the same issue can happen if the cable is routed backwards. Which again, would be hard to do.
I don't know what every ground on the car goes with. I wish I did. Because your issue still could be grounding related. How did you "check and clean" the car grounds?
Here is the deal, you have already wasted at least $200 on parts you probably didn't need. Spend about $15 more and get a multimeter. Trying to find a charging system problem without one is insanity defined. IMO it is best to check everything both for continuity and for voltage drop.

Recheck engine compartment fuses 2,10,31,32 and 69. And instrument panel fuses 3,8,9,10,23 and 24.
Check the alternator and ECM pin connectors. This ties into your theory on the voltage regulator. You have to understand your car has no voltage regulator, per say. Both the ECM and BCM work together to "command" the alternator output.


Ray Morley said:


> Yes Johnny you are correct. Turning on the High Beams would demand more power output.


Yes of course, them being on will draw more power. But that wasn't what I was trying to tell you. The logic that controls the alternator voltage output will always "command" at least 13.9 to 14.1 volts when the high beams are on (this is regardless of the actual current draw). Hence is should give you a good test point to verify.

Now for some theories.
1. New alternator was broke out of box.
2. New alternator burned up trying to charge a dead battery.
3. You have a load not being accounted for by the current sensor. For example add-on LED headlights, stereo amplifier, etc.
4. You missed checking a fuse or ground. It only takes one fault.


----------



## Ray Morley (May 10, 2021)

Poor wording on my part. Sorry. The Neg cable runs down and thru the round opening on the sensor and then to the front grounding stud. I will recheck the suggested fuses. Where is the ECM pin connector located?

The car is a basic LT with no add ons.

Ground points. I can see the obvious ones. Can you suggest any that might be slightly hidden. 

I cleaned the grounding points and connectors with emery paper until shiny and used electrical spray also.

Let me try this and I will get back to the forum in a couple of days with some Voltmeter numbers.


----------



## Blasirl (Mar 31, 2015)

Service Bulletin - NHTSA SB-10057574-8899
SB-10089945-2280
*How-To: Installation of the Big 3 Cruze Kit*
Clean the Terminals
Cruze Battery Upgrade Options 

The sensor you have been referring to is a Hall Effect sensor. Any ground cables added need to run through this so the vehicle can account for all of the amperage being used. If it is not able to do this, it thinks there is a short somewhere.


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> Where is the ECM pin connector located?















Ray Morley said:


> used electrical spray also


The spray that evaporates quickly, and leaves no residue? Like contact cleaner? The reason I'm asking is because many people don't know dielectric sprays and greases are insulators.



Ray Morley said:


> Can you suggest any that might be slightly hidden.


Well, just be aware the base of the alternator is the (most important) DC negative path. When installing ensure the mounting points are clean just like any other ground on the car.











Blasirl said:


> The sensor you have been referring to is a Hall Effect sensor


fancy talk for a DC amp sensor


----------



## Ray Morley (May 10, 2021)

Thanks for the photo if the ECM. I always had thought it was called a ECU but I did actually know its location. I will update my results in a few days as I am out of town right now at work. Thanks for the help so far.


----------



## Johnny B (Jun 4, 2019)

Unit, module. Potato, patato.


----------



## Blasirl (Mar 31, 2015)

Johnny B said:


> The spray that evaporates quickly, and leaves no residue? Like contact cleaner? The reason I'm asking is because many people don't know dielectric sprays and greases are insulators.
> 
> fancy talk for a DC amp sensor


Yes they are, but when you have parts that are made to fit together well / tightly, it is better to use a dielectric grease to keep out moisture and such. The grease will not interfere with parts that still have decent mating surfaces.

That is what it is called.


----------



## Ray Morley (May 10, 2021)

So the drama continues.

All the fuses have been checked over.

Here are some numbers of what I am seeing.

Vehicle Off
12.12 V at the battery

12.12 V at the alternator

Vehicle Running

11.95 V at the battery

11.92 at the alternator

Now with the vehicle running if I disconnect the positive cable at the connection where it first comes up the battery box I get 14.9 V from the alternator.

Could my issue be a bad or corroded connection where the main positive cable meets the starter?


----------



## Johnny B (Jun 4, 2019)

Ok great, I was hoping you would get back with some numbers.


Ray Morley said:


> Could my issue be a bad or corroded connection where the main positive cable meets the starter?


I doubt it because the car starts, if it were grounded it probably wouldn't. But, at this point I'm not saying anything 100%.

Back in the day disconnecting the battery while the car was running was a great test of the alternator. These days from what I have read, it isn't good to do that . Just a warning.

The measurements are a start, but to be honest to really help you I need more descriptive test locations. Pictures would be nice. Also, I need to know something. Do you understand the concept of a "voltage drop" between components? If not I'll try to explain. For now I'll assume you don't.

With the car OFF. Using the ohm (resistance) function, place one meter lead on #1 and the other on #2. The reading should be less than 1 ohm.
With the car Running. Using the DC voltage function, place on meter lead on #1 and the other on #2. The reading should less than about 0.3 volts.

If either don't jive, that fuse is bad.
Also, since I'm not sure which fuse goes to the alternator check them all this way. From post #1 to the remaining posts.

Ok, get measuring


----------



## Ray Morley (May 10, 2021)

I did exactly as you said and all the readings were well within the parameters. We have another Cruze that works perfectly so I swapped the module over from the good car and nothing improved.

I installed the module from the problem car onto the good car and it worked perfectly. So we know the pictured module and the current limiters are fine.


----------



## Johnny B (Jun 4, 2019)

Well, your car is starting to irritate me also. Ok here we go Ray, hang on we'll get this.
Just a heads up, I'm just going to have you do more testing now rather than piece meal it later.
Test points: 1 = battery positive post 2= battery negative post 3= alternator (positive) output stud 4= frame near ground cable

With the car OFF.
1. Test DC voltage from 1 to 2 
2. Test DC voltage from 1 to 3
3. Test DC voltage from 1 to 4
4. Test ohms from 1 to 2
5. Test ohms from 1 to 3
6. Test ohms from 2 to 4
7. Test ohms from 2 to alternator housing. (preferably the back near the output stud)

With the car RUNNING. (also turn on headlights, vent fan to 3/4 speed, and rear defroster - this is just to create load to amplify voltage drops)
8. Test DC voltage from 3 to alternator housing
9. Test DC voltage from 3 to 1
10. Test DC voltage from 3 to 2
11. Test DC voltage from 3 to 4
12. Test AC voltage from 3 to alternator housing (yes, AC voltage)
13. Test AC voltage from 1 to 2










With the car still RUNNING.
A= middle of post B= cable connector

14. Test DC voltage from A to B on negative battery post
15. Test DC voltage from A to B on positive battery post










It may seem like a lot, but it won't take but 10 minutes to test. But please double check all readings, and list them 1-15.


----------



## Thebigzeus (Dec 2, 2018)

Nice write up


----------



## Ray Morley (May 10, 2021)

Hey Johnny. 

You are an asset to this forum.

So before I do any testing as rcmd we discovered something today that we did not notice before.

We had the voltmeter connected to the main pos/neg battery terminals. We loosened the neg connector slightly and moved it 1/2 way up the post and the voltage jumped to 14.9 volts. When we pushed the terminal back down it went down to 11.8 volts.

My friend Craig notice that the small black wire that leads off of the neg connector to the BCM had black wrapping on it that was not factory so a DIY repair had been made. We properly repaired that terminal end.

So while driving the BATT light cycled on and off a few times. I checked the battery voltage engine off and the battery had 11.9. My guess driving it and only getting a very small charge has killed it off. I put the original battery back in it that has 12.5 volts and so far engine running the voltage is showing 14.7.

I will keep you updated.


----------



## Ray Morley (May 10, 2021)

And here is the update.........

It worked normal until I started to drive it and the BATT light came on again.


----------



## Ray Morley (May 10, 2021)

I put the weaker battery back in to see if the voltage would increase to charge it up but the voltage did not increase.

I did the test and double checked the numbers.

1/ 12.15

2/ 12.15

3/ 12.15

4/ 57.1

5/ 57.1

6/ 0

7/ 57.1

8/ 14.2 to 14.7

9/ 0

10/ 12.37

11/ 12.49

12/ 0

13/ 0

14 and 15 questions confused me on exactly what you want me to do


----------



## Ray Morley (May 10, 2021)

I just put in a good battery showing 12.77 engine off. Start the car and the voltage taken at the same point drops to 11.8.


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> 14 and 15 questions confused me on exactly what you want me to do


Ya, I figured those would. That is testing for a voltage drop between the battery post and the cable connector. The voltage drop should be zero (or less than 0.2 volts), if there is a voltage drop it means there is corrosion or a loose fitment.

Earlier you mentioned moving the negative battery connector, that fine but realize the posts are slightly cone shaped. The further down the connector is, the better (within reason). If you tighten the connectors on the very top of the post, you will distort the connector. It too is slightly angled, when paired properly they share maximum surface area. And that is what you want.

Well, we have a smoking gun!!!!! TEST #5 

Test 5 should have been less than 1 ohm. The cable has an issue. It might have a bad fitting, a big cut, burned up internally, something. The issue has to be with this cable, it might even have rubbed through shorting against the engine, or some other metal piece. This would explain reading #7.

Also, test 8 tells me the alternator is is working.

We are almost there.


----------



## Ray Morley (May 10, 2021)

I will re-test 5 and 7 again but I initially double checked the results and those results are exactly the same from 2 totally different spots.

5 and 7 tested for ohms engine off

new numbers

5/ 00.7

7/ 02.7

Why such a drastic difference from the first set of tests?


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> Why such a drastic difference from the first set of tests?


Well, to be honest you are most likely not testing the way I asked. Maybe.

If you measure test point 5 from the case, instead of the post, to the positive battery post. You will actually be testing the resistance of the diode set in the alternator, and about 50 ohms seems reasonable. But since diodes "should" only conduct one way, I'm pretty sure we just checked the alternator good a 3rd way. hehe Anyway, what you probably did is reverse the polarity of your reading. Placing the black lead on the positive battery post and the red lead on the alternator case will give you a higher resistance reading, if the battery negative is disconnected.

Well, I'm honestly a little confused now. Because the alternator is working fine ( test 8, 12, and 13 prove it). Also, it is is clear the battery is NOT being charged ( tests 10 and 11). Yet all the ohm readings look good NOW. arrg. Also, I'm very confident both your batteries are good. So that bring us back to the wiring and fuses.

You are making the voltage but its not getting it to the battery. And test 6 and 7 tell me the grounding is good. So you just need to track every bit of the red cable from the alternator to the battery. 
Take some pictures for me, please.

With the car running do some more checking.
1. DC voltage 1 to 2
2. DC voltage 1 to 4
Check out the the fusible link box on page 15.
3. DC voltage from #2 (on page 15) to battery negative post.
4. DC voltage from #1 to to negative battery post.

We just need to find where the 14-15 VDC is getting stopped.
And just to verify, you tested all 6 fusible links on page 15?

Also, you never got back on test 14 and 15.


----------



## Ray Morley (May 10, 2021)

Before I head to bed I re checked and #5 and #7 test are showing the lower readings. I assume I am doing the ohm check correctly. I have the rotary dial set at the 20 position. I place the red end of the tester on the alternator positive stud and then the black connector on the positive main wire connector where it comes up from the starter to the battery box.

All items on Page 15 checked out perfectly.

Here are the results of your recent test request.

1/ 11.79

2/ 11.77

3/ 11.67

4/ 11.64


----------



## Ray Morley (May 10, 2021)

I took 2 photos of a live run and the photo from 11.093 to 11.127 was right when the BATT light came on.

Within a minute it went from 11.127 right down to 10.790.

Que


----------



## Ray Morley (May 10, 2021)

With the car off the Batt is showing 11.9 volts. It was brand new last week at 12.6.

Car running.

1 to 3 is 11.72

1 to 4 is 11.73

From the original long list of checks I did #8 again. From the alt pos stud to the alt case. It showed when I tested it 14.2.

However when I check from the alt post stud directly to a body ground I am only showing 11.8


----------



## Johnny B (Jun 4, 2019)

Well, the alternator voltage isn't even making it to the battery fusible link box. But we are still at the same place, the alternator is working but the voltage isn't making it to the battery.



Ray Morley said:


> However when I check from the alt post stud directly to a body ground I am only showing 11.8


Even though we tested the resistance of this route, voltage drop is more telling. Which is why I wanted you test using both methods. Maybe you do have a grounding issue.
When the alternator was installed, was any grease used? The thing is the alternator is grounded through the case, through the mounts, to the chassis and on to the battery. And grease, oil, or what ever, can act as an insulator. And the 11.8 volts tell me the alternator and battery grounds are not shared, this is bad.

If you have jumper cables ( or really any cable over about 14 gauge) connect the engine lifting mount to the battery frame mount. This will supplement/replace the ground that "should" be on the engine, again I wish I knew where all the grounds are.

Doing this might work, afterwards take some readings.











Just keep these things is mind, because it isn't really intuitive. When the car is off (and during starting) the battery is the source of power, and the battery posts are the most negative and positive thing in the electrical system. When the car is running the most negative and positive thing in the electrical system shifts to the alternator. So now, when the car is running, the alternator positive post and the alternator case (negative) are the new power source. And since the alternator voltage is controlled at about 14 VDC the battery will charge because it is at 12-13VDC.


----------



## Ray Morley (May 10, 2021)

I used brand new jumper cables I had. I started up and tried it on both lift mounts (separately) with the other end connected to the battery tray and I also tried the ground where the neg battery cable goes to. I am still only showing the voltage of the battery of 12.2 volts.

When we installed the alternator we did use some spray lubricant to enable the unit to slide into the brackets easier as they were quite snug. I never realized this may have been a bad idea.

Would the bypass you suggested circumnavigate this issue if that was causing the problem?

QUESTION: If the possibilty exists the Alternator has a bad ground would this idea work?

Attach one end of the booster cable to the alternator mounting bracket and the other end to a ground such as the lifting mount or another body ground that is clean?

ANSWER: Car running. I did not have 14 guage wire but I had something suitable that could at least give me a reading.

I attached one end of the booster cable to a body ground. I could not attach the other end directly onto the Alt frame due to size issues but I used the wire I had and secured it in the clamp of the other end of the booster cable and then touched the other end to the alternator body near the support mounts.

Yikes. The end of the wire started to glow and spark but we did see the voltage jump up to over 14 volts on the voltmeter.

The voltmeter was taking the reading between the pos and neg post on the battery. So by doing that my reading went from 12.2 right up to 14.2 right away.


----------



## Johnny B (Jun 4, 2019)

Ray Morley said:


> Attach one end of the booster cable to the alternator mounting bracket and the other end to a ground such as the lifting mount or another body ground that is clean?


Yes, that should work. If not go from the alternator mounting bracket to the frame ground. Or you could try this last, but be careful. Go from the alternator mounting bracket directly to the battery negative post. Just watch out for the belt and make (or break) the connection while the car is off.



Ray Morley said:


> When we installed the alternator we did use some spray lubricant to enable the unit to slide into the brackets easier as they were quite snug. I never realized this may have been a bad idea.


One of the *biggest* misconceptions I see is the average person doesn't realize that 99% of all spray lubricants, greases and lubes are to some degree insulators. And IMO when people see something like "dielectric" or "electrical silicone lubricant" they think, OOOOHHHH this must help with electrical conductivity!!! And are fooled because of its different wording, but the truth is they are just BETTER insulators. But they don't know, so they slop it on spark plugs and every other thing not realizing wtf they are doing. Then their car doesn't work afterwards and they can't understand why. The best part is I could easily find a dozen Youtube videos right now with fake experts telling people use lubes wrong, but the video say up and the fake experts keep racking up the views. lol


----------



## Ray Morley (May 10, 2021)

Like I mentioned I was seeing a lot more voltage at the battery when doing the Alt bracket to a body ground. In fact this may have also been the original problem with the BATT light coming on and why we changed the Alternator in the first place as the problem remained the same after the Alt change.

The Alternator is held into the mounting bracket by 2 long bolts. If I unscrew each bolt slightly (one at a time) and by using 14 guage or better wire can I use a 'U' connector on the bolt end and an 'O' connector at the other end and ground the wire at a different spot on the engine or frame? I can probably do both bolts so I would have 2 separate ground points?

If we take the Alternator totally out and clean up any residue we will not be able to get it back into the bracket for sure so if my idea will work I think I would like to try this first.


----------



## Johnny B (Jun 4, 2019)

I can tell by your questions, you are really understanding the the problem now. 🆒 




Ray Morley said:


> I attached one end of the booster cable to a body ground. I could not attach the other end directly onto the Alt frame due to size issues but I used the wire I had and secured it in the clamp of the other end of the booster cable and then touched the other end to the alternator body near the support mounts.
> 
> Yikes. The end of the wire started to glow and spark but we did see the voltage jump up to over 14 volts on the voltmeter.
> 
> The voltmeter was taking the reading between the pos and neg post on the battery. So by doing that my reading went from 12.2 right up to 14.2 right away.


OMG!!! I missed this before. Its hard to say, but it sounds good actually. We are on the something. Keep in mind, it doesn't take much at all to cause sparking. And your batteries are getting so low in voltage they are going to draw ALOT of current. Just don't ever put a cable between a neg and pos location.

Well, what I would do is take the alternator back out. Clean the mounting point with solvent (just use stuff that leaves no residue, like alcohol) , I'd even lightly sand the the surfaces that connect to the engine mounts, and same for the engine mounts. Clean the output post and the cable connector. Then re-install, hopefully this fixes it.

If not..............................



Ray Morley said:


> If I unscrew each bolt slightly (one at a time) and by using 14 guage or better wire can I use a 'U' connector on the bolt end and an 'O' connector at the other end and ground the wire at a different spot on the engine or frame


Hehe, you are a genius. What you have just described is part of what most people call the "Big3" or "Big4" upgrade, just google it  
You could do that, but first I would do what many Cruze owners do first.

Near that engine lift mount there should be an extra hole in the engine block. Then put in a M8x20 bolt and run a 10 gauge (or larger) cable from there to the battery ground frame bolt, that is a good engine ground upgrade.


----------



## Ray Morley (May 10, 2021)

Near that engine lift mount there should be an extra hole in the engine block. Then put in a M8x20 bolt and run a 10 gauge (or larger) cable from there to the battery ground frame bolt, that is a good engine ground upgrade. 


Yes. I can do this mod easily but it still would not solve the problem I have now as it would not ground the Alternator. I looks like te Alt will have to come out and be cleaned up.


----------



## Ray Morley (May 10, 2021)

Heading to my buddies today to take the Alternator out and totally clean and lightly sand all the contact points and also try to add an additional ground point from the Alt to the engine. I just did a run test from the Alt positive stud to the Alt casing and the voltage was rock solid at 14.0 volts. So the Alt is producing the voltage.

I did a test from the car body to the Alt casing (simulate a new grounding) and the reading at the battery (post to post) went from 11.9 up to 12.7.

Not a great increase but with luck we should be able to get this thing working.

My guess is the increase only went up to 12.7 was because the simulated ground on the Alt casing was not super tight OR the RVC commanded only 12.7 volts out of the Alternator.


----------



## Ray Morley (May 10, 2021)

SUCCESS

We removed the Alternator and cleaned everything up. It was not too bad overall.

We did do an interesting mod with the Grounds.

We used high guage wire and proper connectors and ran a ground from the upper and also the lower mounting bolts to a common spot on the aft engine compartment body.

She is putting out the volts now. The battery is actually getting a bit overcharged but this is probably because it had been taking some drastic hit with voltage loss. I will monitor it and see what happens.

Johnny you did a great job in coaching me and I feel confident I can trouble shoot any other issues with the charging system.


----------



## Johnny B (Jun 4, 2019)

Finally !!!! 😎

I must say I haven't known anyone that has lost the engine ground so completely. Next time I get under my car I'm going find my engine ground, this was crazy what we went through.
I'm glad I was able to teach you something.



Ray Morley said:


> She is putting out the volts now. The battery is actually getting a bit overcharged but this is probably because it had been taking some drastic hit with voltage loss. I will monitor it and see what happens.


The computer (PCM and BCM) actually keeps track of battery charge levels, so it should keep the battery pretty much where it needs to be.


----------



## Ray Morley (May 10, 2021)

I really did not know much about electronics but once I started to grasp the concept it became easier for to understand the theory behind it. Right up to realizing that I could use some simple wiring to simulate a new Alternator ground which then proved the real ground on the mounting procedure was the main issue.


----------

