Sparky
Member
- Dec 4, 2011
- 12,927
Stand Alone Regulated Voltage Control (SARVC)
https://gmtnation.com/forums/threads/regulated-voltage-control.7999/
https://gmtnation.com/forums/threads/regulated-voltage-control.7999/
I was wondering if there might also be a Mechanical Cause that is directly involved with the Charging System, This video gives a very interesting look at and explanation of two other possible causes towards the very end of the film that are worth seeing:
NP... But I'd Bet Coin that your OEM Serpentine Belt Tensioner has seen better days... That Power Plant you have looks Pretty Mean and Punchy in your Profile... and I'd also bet that when you press down on the "Green Means Go... Pad" ... the wound coiled steel spring inside that thing down there sheds blood. FWIW... This ACDelco Pro Version is on Sale right now via this Link... Just something simple to R&R and to check off a box on your WTFIW? list... ;>)
https://www.amazon.com/ACDelco-38158-Professional-Automatic-Tensioner/dp/B000C9PFJK/ref=au_as_r?_encoding=UTF8&Make=Chevrolet|47&Model=Trailblazer|489&Year=2007|2007&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=1&vehicleType=automotive
I know you replaced the alternator but maybe take it in for testing. Maybe it`s a dud. it happens.
Take a look at THIS:
http://www.tbssowners.com/forums/tsb-recall-sections/224434-headlight-relay-2008-tbss-print.html
https://www.amazon.com/dp/B0065S6S8Y/?tag=gmtnation-20
Here are (2) of (189) Customer Reviews from Amazon:
5.0 out of 5 stars Replacement for 2008 Envoy Denali -- headlight relay module
ByEngrKaton January 20, 2015
Verified Purchase
Purchased for an 2008 Envoy Denali which had intermittent low beam issues. Was an easy drop in replacement. Been installed for a couple of months now and the issue has not resurfaced.
4.0 out of 5 stars ACDelco 15016745 OE Service Headlamp Relay
ByRRon January 20, 2014
Verified Purchase
One time on the freeway at night ...both my low beams flickered. About a week later, both my low beams died while pulling into my neighborhood. I was aware this relay is known to fail so I replaced it. Have not had any problems since.
View attachment 83226
You've probably eye-balled this thread already... but JIK not...
https://gmtnation.com/forums/threads/big-3-upgrade-250amp-ho-alternator.9592/
Here are a Few More Ideas for you to Beat Hell out of…
In the later model Trailblazers and Envoys… When running in Daylight Driving Mode… The Headlights use PWM (Pulse Width Modulation) at around a 70% Duty Cycle ...and that can make them appear to ‘flicker’. Investigating “What’s Up?” with that circuit might lead to other discoveries of sub-electrical system components that are doing likewise… but at night time.... when the problem would be most apparent.
Next… On the subject of Parasitic Draw/Drain as being a possible contender involved by way of weakening your over night battery storage:
http://flashoffroad.com/electrical/CurrentDrain/currentdrain.pdf
Parasitic Drain Tester:
https://www.amazon.com/s/?ie=UTF8&k...qmt=p&hvbmt=bp&hvdev=c&ref=pd_sl_4ch3xyje3h_p
And on the Subject of “What is ‘Normal Parasitic Drain’..?”:
If you have a decent Wiring Diagram... try to locate the positions of Ground #102 and #201 and after removing them and cleaning them right down to bare metal and re-attaching them with a drop of Dielectric Grease... perhaps approaching this problem "From the Grounds Up" ...might cast a brighter light on the solution:
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I'm out of ideas.
What do you mean a "clutch drive"? Never heard of that on an alternator.
So just taking a wild stab. Could it be the voltage sensing wire that's wonky? Bad contact or wire? Obviously the alternator is doing this for some reason.
IIANM one of our better known Members… @MAY03LT had made some major changes to his power set up with the advent of some bigger sound amplification… you can actually see some of what his under-hood wiring looks like in how robust his changes were… perhaps he has some of his videos over on his Youtube Channel that will address this as well.
You’ll recognize this as your own quote posted on another forum on 02/12/2018 in your quest to solve this annoyance… and it actually gives some important clues that bear out @Mooseman ‘s suspicion of a sketchy Alternator Signal Wire. It also might return the attention to the need for a different kind of battery if the one in-dwelling has hidden dead cell or over-charging damage issues.
“Well, I just tried throughly cleaning grounds 102 and 201 and the grounding block under the console on the inside, no change. Even disconnected all the extras I added such as the efans, alky injection, IC pump, etc, no change.
Also decided to try for shits and giggles... removing the belt there is no flicker. Removing the battery power wire on the alternator no flicker. Yet if I swap alternators again it will still flicker. Makes absolutely no sense at all. Only thing I wonder, with the minor electrical additions I have do I need a bigger HO alternator? Other than that I have nothing.”
http://www.tbssowners.com/forums/el...-flickering-light-issues-need-help-print.html
This is yet another Long Shot Suggestion.... But what about replacing your Fuse Box Junction... Lock, Stock and Barrel... and Start Fresh where all of these competing electrical connections 'Hover Under Cover' and see if that makes any difference. Perhaps you can pick one up that is newer with a full set of Relays and Fuses...and not transfer anything from the Old Unit during this Heart Transplant?
This is yet another Long Shot Suggestion.... But what about replacing your Fuse Box Junction... Lock, Stock and Barrel... and Start Fresh where all of these competing electrical connections 'Hover Under Cover' and see if that makes any difference. Perhaps you can pick one up that is newer with a full set of Relays and Fuses...and not transfer anything from the Old Unit during this Heart Transplant?
Mini hijack. I just learned today about Alternator Decoupler Pulleys or clutches. Sounds like a good idea but just another thing to break or replace with the belt and tensioner.
Probably a pricey shot in the dark. First, TBSS's are difficult to find in yards and second, a new one is probably a few bills. Kind of a drastic measure for a problem it might not even solve. Possible that a 5.3L box and harness is the same.
Even smaller hijack. My brother-in-law has an 08 tbss that i drive and work on all the time it's pretty bone stock with the addition of an after market amp,sub and speakers all the way around and we have never experienced this at all. The only time is we do get the lights to go dim on the dash is when we hit the window button and the window is maxed out to the top. Then again my 08 Envoy does the same.
On both the Voy and tb when we got our music thumping at high volume because of the bass is when we could get the headlights to dim down a bit. We aren't running high output alternators or batteries just 5fared caps. He's got just over 75000 miles on his and I've got just shy of 165000 on mine.
Unless I saw wrong, that's for a 4.2. Definitely will not interchange.