Ataristic 5 Posted September 18, 2013 Share Posted September 18, 2013 Has anyone else noticed this? At night, with headlights on, if I lower or raise a window, the headlights and panel lights will dim slightly, hardly noticeable but I can see it. If I work the switches two at a time, the effect is a lot more noticeable, nothing shocking like driving with no lights but there is a dimming effect while the motors are working, same goes if I work the switches past the down or up position, as soon as I let go of the switches, the lights go back to normal. I understand the window motors will put load on the electrical system, but shoud it be enough to cause this effect? Link to post Share on other sites
Greg_E 211 Posted September 18, 2013 Share Posted September 18, 2013 I have not seen this while driving, but at idle yes I see this too. Link to post Share on other sites
bluer101 241 Posted September 18, 2013 Share Posted September 18, 2013 Normal. Link to post Share on other sites
Lovgun7 75 Posted September 18, 2013 Share Posted September 18, 2013 Normal. +1 seen it... its nothing Link to post Share on other sites
austex04 48 Posted September 18, 2013 Share Posted September 18, 2013 Power windows draw quite a bit of power, so do things such as rear window defoggers and seat warmers. It's normal for things to dim a bit at idle when using these items. The battery is making up for what power the alternator can't produce at low engine rpm. Which is why I don't have the a/c blower set on 4 or the rear defrost on unless I'm moving, it saves the battery and less wear on the alternator. Link to post Share on other sites
Ataristic 5 Posted September 18, 2013 Author Share Posted September 18, 2013 The thing is , I notice this both at idle and at highway speeds, those of you that say this is normal, have you seen this while at highway speeds? Link to post Share on other sites
Greg_E 211 Posted September 19, 2013 Share Posted September 19, 2013 No, not at speed so you might want to have the stealership take a look at the charging system. Even with fogs on (70 additional watts) I don't see them dim when I operate the windows at speed. Link to post Share on other sites
WaltK 305 Posted September 19, 2013 Share Posted September 19, 2013 I read your post earlier in the day, I had to go out for a bit, so I started playing with my windows, with lights and fogs on, both on the highway, and at idle. I didn't see any variations at all, the interior, and exterior lights remained constant. I hate to be the one to throw a damper on things, but better you get it checked out, in case there is a problem with the charging system. Link to post Share on other sites
Ataristic 5 Posted September 19, 2013 Author Share Posted September 19, 2013 Just came back from the dealer, they are telling me this is normal operation, they called the tech center at GM and they where told this is also normal operation. The dealer provided me with a techlink document applicable to all models indicating extra electrical load effects at idle , albeit it is dated 2009. supposedly the alternator regulator on these cars is controlled by the ECM, so it does not excite at a specific RPM as traditional alternators do, this means the alternator is actually not charging all the time at high RPM as in traditional alternator designs, this is done to save fuel. I am not filled with confidence since they told me they no longer test alternators using Snapon D-tac 2, at least I got an incident number out of it. Link to post Share on other sites
Greg_E 211 Posted September 19, 2013 Share Posted September 19, 2013 Hmmm..., sure wish that stupid service manual was available. Link to post Share on other sites
austex04 48 Posted September 19, 2013 Share Posted September 19, 2013 The thing is , I notice this both at idle and at highway speeds, those of you that say this is normal, have you seen this while at highway speeds? Yes, mine will do this on the hwy as well, so did my old car. I wouldn't worry about it. Link to post Share on other sites
Ataristic 5 Posted September 20, 2013 Author Share Posted September 20, 2013 Yes, mine will do this on the hwy as well, so did my old car. I wouldn't worry about it. thanks man, I will not bother with it anymore. Link to post Share on other sites
Silver Spark 1 Posted February 15, 2014 Share Posted February 15, 2014 (edited) I noticed my headlights brighten when taking off from a stop. The ECU should crank up the output on the alternator to create enough power so you never see it dim. On my other car (A Honda Fit) had weak starting from new and I found there was a poor connection from the frame to the engine. I added a 4 gauge wire there and it works great now! It seems the problem might be that the ECU cannot see the voltage loss creating the dimming. Once the weather warms up here I can take a look at the situation with the Spark... Edited February 15, 2014 by Silver Spark Link to post Share on other sites
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now