Chevrolet Cruze Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
I've been trying to chase this electrical issue for months now. When I'm driving the screen shows anywhere from 11-15v depending on if I'm on the gas or not. When I'm at idle it slowly drops to 12 or below. The headlights and dome light also are dimming and flickering very bad, so much so that I'm not comfortable driving at night in it. I've replaced the alternator twice, as well as tested the mskt recent one, just tested the battery as well as cleaned the terminals and the ground point for the negative lead. I also just put a new current sensor just to be sure, but it did not improve anything.
 

·
Registered
Joined
·
3,216 Posts
You're diagnosing a normal routine. Although 11 is kind of low.

Use an actual voltmeter and see it if reads different then the dash. They usually do.

Cars today don't put out a constant charge like yesterday's cars.
 

·
Registered
Joined
·
157 Posts
I'm "old school"...in both the newer car knowledge and age. In the past, what you describe could be what was called a "voltage regulator"....usually located on the firewall....a black box with (sometimes) an adjustment screw. With these newer computer controlled cars, I have no idea if the CRUZE even has one or perhaps it is built into something else. (Wondering if your "current sensor" is another name for voltage regulator))
 

·
Super Moderator
2014 LT program car, Pull Me Over Red
Joined
·
11,223 Posts
I've been trying to chase this electrical issue for months now. When I'm driving the screen shows anywhere from 11-15v depending on if I'm on the gas or not. When I'm at idle it slowly drops to 12 or below. The headlights and dome light also are dimming and flickering very bad, so much so that I'm not comfortable driving at night in it. I've replaced the alternator twice, as well as tested the mskt recent one, just tested the battery as well as cleaned the terminals and the ground point for the negative lead. I also just put a new current sensor just to be sure, but it did not improve anything.
Welcome Aboard!(y)

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

don't forget to introduce yourself and your Cruze here.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #5 ·
I understand the electrical system voltage varies while driving, and it's done it before when it was running normally, but currently it just drops and continues passed when the battery light comes on. The lowest I've seen it the last few weeks was 10.5 or so when I drove to work in the cold. Battery light stayed on.

The voltage regpp0las far as I know is either in the alternator or the ECM, the current sensor is located wrappered around battery ground wire.
 

·
Premium Member
2013 Cruze LT
Joined
·
3,216 Posts
Have you had the alternator tested?
 

·
Registered
Joined
·
139 Posts
The lowest I've seen it the last few weeks was 10.5 or so when I drove to work in the cold. Battery light stayed on.
You definitely have a problem, you should really never see the voltage go below about 12.5V -ish.

I just finished helping Ray with problem that has very similar symptoms. Please read through the post, the solution is near the end. I can help you also, but you need a multimeter.

 

·
Premium Member
2013 Cruze LT
Joined
·
3,216 Posts
Have you verified it at idle with a volt meter? To be sure it’s not just the ECM mis measuring.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #10 ·
You definitely have a problem, you should really never see the voltage go below about 12.5V -ish.

I just finished helping Ray with problem that has very similar symptoms. Please read through the post, the solution is near the end. I can help you also, but you need a multimeter.


So I should start up next by measuring everything with a voltmeter I guess (Im not great at electrical so this will be a process lol) then check the contact points on my alternator and potentially running grounds from there to the body? Before I move on to the big 3 kit? The issues ray had seem similar to mine so hopefully I won't be on this wild goose chase much longer
 

·
Registered
Joined
·
139 Posts
Well, you don't have to measure everything. But if you don't, I have to make assumptions. He was just like you, and many others coming here for help. You have replaced parts that were never never bad and over again, and then still have a broken car. Just being honest, its a daily event here.

Anyway....testing. I'm assume you lost the grounding to the battery from the alternator, like Ray.
1. Test the voltage for the alternator. Go from the alternator output stud to the alternator case, should be about 14.
2. Test the voltage from the output stud to the battery negative. If the reading is now about 12, you lost the grounding.

Probably the easiest thing to try first is one part of the Big3. Just add a ground, from the engine block to the frame.

292507



 

·
Registered
Joined
·
9 Posts
Discussion Starter · #13 ·
Okay I ran a ground from block to frame, gave a quick drive and the interior electrical seemed to flicker less if at all, but the screen voltage display did show decrease as I accelerated all the way down to 12.0v. Will drive again later to check headlights at night
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #15 ·
Okay after adding the ground from body to block it did not improve any of the flickering of the lights, or the battery decrease when accelerating. I went ahead and hit it with the multimeter across all 15 points you listed in rays post.

Here are my readings


1. 12.67
2. 0.00
3. 12.69
4. OL
5. 0.02
6. 0.01
7. 0.01

8.15.1
9. 0.05
10. 14.5
11. 14.5
12. 0.10
13. 0.05

14. 0.0
15. 0.0

I did measure and double check each time, hopefully I didn't mess up any of it but that's what I got. Although I'm still not sure what my next step may be, if I should go ahead and "big 3" the wiring or if maybe my ecm is screwing up or anything
 

·
Registered
Joined
·
3 Posts
The situation sounds like an issue with the ecm not properly controlling the alternator correctly. I suggest you have someone with a scanner (not a code reader) check the alternator function via the ecm
 

·
Registered
Joined
·
139 Posts
The situation sounds like an issue with the ecm not properly controlling the alternator correctly. I suggest you have someone with a scanner (not a code reader) check the alternator function via the ecm
I disagree. The alternator is working, or seems to be by your readings. And to me that means the ECM is working fine (they usually do). That said, cleaning the pin / pin connector for the ECM is a good idea. And maybe check the connector on the alternator itself.

BTW, I fell asleep way early last night. I didn't have a chance to get back to you :(

Anyway, reading the codes on your car is NEVER a bad idea.

Ok, now the bad news. All of your readings look fine. I don't get it.

Do you have anything extra on your car? Lights, stereo amp, etc.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #18 ·
The situation sounds like an issue with the ecm not properly controlling the alternator correctly. I suggest you have someone with a scanner (not a code reader) check the alternator function via the ecm
I disagree. The alternator is working, or seems to be by your readings. And to me that means the ECM is working fine (they usually do). That said, cleaning the pin / pin connector for the ECM is a good idea. And maybe check the connector on the alternator itself.

BTW, I fell asleep way early last night. I didn't have a chance to get back to you :(

Anyway, reading the codes on your car is NEVER a bad idea.

Ok, now the bad news. All of your readings look fine. I don't get it.

Do you have anything extra on your car? Lights, stereo amp, etc.
No rush dude! And no i don't have anything extra like that, honestly just my rear defrost drops the voltage bad enough that I haven't even thought about amps or subs or anytging. Although seems to be fine at idle like 75 percent of the time, sometimes at a red light or stop sign it will start to drop by like .3v every two seconds or so. However every time I accelerate, usually a but above 2500rpm it starts dropping until I let off entirely. It seems to have gotten a little less intense with the new ground cable now that I've been watching it a day or so. The battery light hasn't come on at least but it did drop to 11.7 at one point, and then charged up to 15.6 another time.

I've checked and cleaned all the fuses and I checked the ecm plugs and pins when I did and they seemed to look OK, but I'll go in and check and clean again to be sure. And I'll unplug and check the alt plug too. Hopefully I get somewhere with it lol
 

·
Registered
Joined
·
139 Posts
at a red light or stop sign it will start to drop by like .3v every two seconds or so. However every time I accelerate, usually a but above 2500rpm it starts dropping until I let off entirely. It seems to have gotten a little less intense with the new ground cable now that I've been watching it a day or so. The battery light hasn't come on at least but it did drop to 11.7 at one point, and then charged up to 15.6 another time.
I got thinking, maybe your problem is mechanical. How does your accessory belt look? Also, does the tensioner seem to be working?
At idle is IMO the worst condition for the alternator. The load on the system is still pretty high and the alternator output is low. So getting even a little slip on the belt might do what you're seeing.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #20 ·
Well it's possible, there is an oil leak I've been chasing pretty much the whole time I've had the car that drips on the belt and pulleys, so it gets spin around the whole left side if the engine. Although it's been that way for a long time and never done this to the electrical before. The issue arose when I changed the valve cover a few months ago, not that the valve cover would do it either, just clarifying lol
 
1 - 20 of 21 Posts
Top