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Voltage Regulator

It seems GM does not want fess up to a on going problem with voltage regulator's. They are integrated in to the Alternator and don't adjust quickly enough went voltage demands change, like when a air pump turns on. This effects lots GM models and they have no urge to fix it as long as it doesn't effect safety. The regulator adjusts gradually instead of instantly causing the lights to flicker or voltage to drop. So all of you with Bad Ass stereo's are getting the worse of this.
 

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I'm not siding with GM (bunch of boobs:rolleyes: ), but I dunno of a car/truck that doesnt do this these days when a hi amp draw kicks in. All voltage regs are built into the alts these days & cars are highly electrical dependant. It's not only GM. My ford does it, my isuzu did it, had a nissan that did it, etc.

Joel
 

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There's a difference

When a GM does it, your usually driving under normal conditions. Furthermore, if you drive alot at night the headlights intermittantly flickering will slowly drive you to the edge of insanity. I sold my '02 OLDS Intrigue because of the problem and got a Honda (which I had a hard time convincing myself to do) and never had a problem close to that. Damn GM!!!:mad: No other car other than newer GM's does it that bad from my experence...
 

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2002 chevy trailblazer_ls
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The feature in alternator voltage regulator that causes this to happen is called "load response control". This feature is in most of the GM (Delco) alternators made in the last 15 years. It is also in many of the Ford alternators with White Case Voltage regulators. It is also in some of the Nippendenso regulators used in Hondas and Toyotas. Basically what is does is control the rate of response of the alternator to increasing electrical loads at low RPM. Notice when parked at less than 1000 RPM, turn on the lights bright and the voltage drops for second and than recovers. They put this feature in many modern alternator so the RPM does not drop when increasing electrical loads. For more detals type the following in google "alternator load response control"
 

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2005 chevy trailblazer_ls
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My TB is plagued by this flickering problem also. The voltage will drop below 12 for a couple of seconds and the headlights/dashlights will pulsate bright and dim during this time. I don't get it all the time, but it probably happens an average of twice a week. The first time it happened it was at night with the wipers on, defroster on, and radio up loud. So I thought I was pulling too much juice. However, since then I caught the voltage dropping during the day with the lights off (except DRLs) and the radio on very low. Clearly this isn't an issue of the owners of these vehicles doing anything wrong. Other cars I've had with giant stereos (~500W amps) never even had such severe voltage drops when the bass hit. It definitely seems like a regulator issue to me. It's very unfortunate that the dealership refuses to acknowledge this problem as one they should correct.
 

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SATBLS said:
... Other cars I've had with giant stereos (~500W amps) never even had such severe voltage drops when the bass hit. It definitely seems like a regulator issue to me...
Your other cars likely didn't have the big azz goofy electric air blower for emissions control like the 4.2L has. That's what causes the spike. When it kicks on. I see on the literature for the 2006's GM says they 'improved' the AIR system. I bet they either increased the efficiency of the electric blower, or segregated it's power spply better.

Joel
 

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OPTIMA will solve everything

I have a optima battery in every vehicle I own and they have enough stored compacity to power through these current drops. It will set you back 100.00 or so, but you probably will never have to replace your battery again. I have been passing one of the batteries from car to car for the last 5 years with no problems.:thumbsup:
 

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I have a 2005 trailblazer LS 4x4, This problem has been going on since november. when the gas is let off, the voltage meter drops, all lights flicker, does it a lot, only at night. took it in to dealer, they had to run tests in a dark room with a test computer, and said that GM was aware and there is nothing that can be done. does anyone else have this problem and had it fixed?? They said is was something to do with the air pump that adjusts the rich/lean of the engine. Something needs to be done here!! people get pissed over flashing lights...
2006 Trailblazer LS 4.2 with same problem for about 2 years or so. Four days ago I took off the throttle body, cleaned it up, and reset the pcm (fuses 10 & 28). Before it was clean the motor would idle at about 400 rpm, and now it idles at about 650 when the motor is warm. Which seems to be just enough to keep everything running good.
I am no tech, just a guy who likes to work on his own sh*t. There is a very good video on you tube, thanks to that guy, my truck runs like freakin' new again (knock on wood).
 

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Hey but the trailblazer is a sweet moving vehicle as long as u keep up the maintainence on it I'm not worried about flickering lights if they don't like it tell them to buy u a new one, it's that matter that it drives and thier isn't anything massive to fix on it keep ur blower turned down then when it gets hot enough turn it up and get it to the spot u like it and turn it back down its that or make something to help with the power and I would buy back then if I knew they had problems sure they wouldn't pass but I'd drive it anyway!
 
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