Lack of power? Electrically

[bergeron007]

New to this forum, new to sonic! How new? I bought my 2013 sonic Hatchback LT 1,4T 6spd manual about 5 hours ago. Love it so far BUT at a stop just sitting there playing with the car I noticed when I hit window switch my headlights dim...a good bit actually. the Slightest drop in RPMs when I go to take off the lights dim. Just seems to weak on electrical power? common or should I have it checked out?


Thank you for your patience on my typing i am on a notebook and hard to type properly.

JB in central PA

2013 Sonic Hatch Back 1.4T 6spd manual cyber Grey
power windows and mylink stereo

 

[ThatTmoGuy]

Depending on how long it sat on the lot, yes its common. If it continues in the next couple of days take it to the dealer.

 

[rdss]

It's an economy car, sitting at idle it takes gas to turn the alternator at full power, I'm thinking they chose economy over power output at idle. Mine does it as well, I also will not roll my windows up or down with the car off unless I have to since it hits the power pretty good as well.

Maybe have Vince bump up the idle rpm if you go with the trifecta tune.

 

[corbetts67]

hold the window switches up when windows are up my lights dim but its no worry i think it will always do that and i have ran my amp and subs off it with the car off and everything works the stock battery is good

 

[bergeron007]

It came off the truck Tuesday. Inspected Wednesday got it tonight so it could be weak. All good points and I see a thread above this one about dead car! So we shall see. It's not a problem for me just so long I know it's common and why you think that.

I will eventually go with Trifecta tune. It's the only tune I am aware of currently but with so many owners running it just seems cut and dry easy answer. But it has 74 miles on it now dont want to void warranty for a little bit. And besides I don't like upgrading right now. If I drive stock power n handling for a bit then upgrade ill feel the difference. If I do it now I have little to compare it too

Ps love the fast responses and appears not many tool bags on this forum. Much appreciated

 

[ThatTmoGuy]

check out the tips on modding thread in my signature, read through at least the first few pages and you'll get a good laugh and insight to usual's around here.

 

[sx sonic]

Welcome to the forum Bergeron007. What you describe does sound normal for our sonics. Let's say I let out the clutch a bit to fast and my idle drops for a second, so will my lights. If I put a sudden load on my car (turn on A/C @ speed 4 or something similar) lights will dim at idle.

if you are concerned that it is excessive you could always check the voltage on the battery as its a quick test and on a new battery voltage almost always reflects its state of health (if no loads/charging has been present for a shot while 12.6V is fully charged/awesome. 12= need some charging time. Low 11= I need a good ole slow charhe for a bit. And idr what dead is, 10 something). Many autosotres will do a load test (better than checking voltage) or you could check the dealer....

Any way I'm wall posting again, its normal for me... so sounds pretty normal, Volt check batter if you can, go dealer if you think its too bad. We're a bunch of goons ;p tune is awesome, and look forward to your integration to the family

 

[$ub$onic]

My ls lights will dim randomly at a stop when the fan kicks in

 

[Eric Smit]

when your fan kicks in the RPMs drop a little below idle momentarily. it's a small displacement flat 4.


-Eric Smit

 

[mowcowbell]

I have a Scangauge II connected to the ODBII port on my '13 Sonic 1.4L LTZ Hatch, and it shows ~14.8 volts at idle. I do notice some dimming too, but figured that is normal for the vehicle.

 

[Chevrolet Customer Care]

New to this forum, new to sonic! How new? I bought my 2013 sonic Hatchback LT 1,4T 6spd manual about 5 hours ago. Love it so far BUT at a stop just sitting there playing with the car I noticed when I hit window switch my headlights dim...a good bit actually. the Slightest drop in RPMs when I go to take off the lights dim. Just seems to weak on electrical power? common or should I have it checked out?


Thank you for your patience on my typing i am on a notebook and hard to type properly.

JB in central PA

2013 Sonic Hatch Back 1.4T 6spd manual cyber Grey
power windows and mylink stereo

Welcome and congratulations on your new Sonic! Sorry to hear you're having an issue already. If the dimming is significant and continues, I would suggest having your dealership check it out.

Vanessa
GM Customer Service

 

[Swordsmith]

The issue is probably one that has already been mentioned, several good suggestions. But a less likely consideration is the automatic lights, which will dim and brighten your internal lights and switch from daylight runnning to headlamps and back somewhat at random in some light conditions, or ir yhou have loose junk on the dash interfering with the sensor in that little dome.

 

[lathia]

I have the same "issue." Although I've experienced it in other cars as well. So I'm not going to make a deal about it, unless I see it gets worse.

Let me ask you since you also have a manual. Does your shift stick rattle when it's on idle and in neutral? Lately I've been noticing this too. Could be the cold temperature or could be that it's normal. It's not TOO loud, but loud enough to be heard. Only way to stop is to set in a gear.

 

[rdss]

Swordsmith, it's when you use the switches and goes away as soon as your done utilizing the switch. It's not the auto lights.

 

[ChrisJ]

I would call it normal.


Alternators cannot produce much output at low rpms. When the engine is idling even a 150A alternator cannot put out more than maybe 20 or 30 amps and thats actually impressive compared to generators from the 1950s.


As others have said producing a draw from the alternator also increases the load on the engine which will cause a slight rpm drop.

When you exceed the amount of current the alternator can output at any given RPM the voltage will drop, the more you exceed it the more it will drop until you are at 12V give or take( battery voltage). Window motors also draw pretty good power, especially when the window is all the way up or down as the motor is essentially jammed.

Here is an example of what kind of power an alternator can output, though these are lower rated alternators then the one in the Sonic. I think the Sonic has something between 105-140A?


Please note this is rotor speed not engine speed. Good chance when the Sonic is idling the alternator is spinning at 1500-2000rpm.

 

[bergeron007]

i did not notice the stick rattling. however i picked it up thursday drove home from dealership which was 2 hours away and then it sat I have not drove it since, needed the tools in my jeep and then got home late so I will keep an eye and ear open tomorrow I have a good bitof driving to do