lights flicker upon startups- '04 Blazer - The 1947 - Present Chevrolet & GMC Truck Message Board Network

65chevysub · 04-23-2015, 05:29 PM

I just noticed on our 04 S10 Blazer that the clearance lights flicker for a bit right after starting then it stops. We had the alternator replaced a couple months ago.
Any ideas and should I be concerned and have the electrical system tested?
Thanks

65chevysub · 08-25-2015, 08:05 PM

Update on my post. All the lights pulsate for a little while after starting(about5 minutes) then it stops. Could this be a ground issue?

cdowns · 08-25-2015, 09:08 PM

Could b a bad ground or just dirty filthey contacts that have not been cleaned and tightened up for years

65chevysub · 08-25-2015, 09:32 PM

Should I start with the neg cable then check all the lights? All the dash lights and exterior lights are pulsating

65chevysub · 10-29-2015, 11:39 AM

Maybe someone can give me some advice. Our 04 Blazer LS developed a draining issue. It's been working fine except the flickering lights. The battery seems to be draining overnight, but there is nothing left on. I cleaned the inside on Monday and accidentally rotated the done light switch on. I figured that out and made sure it is off now. When I get in to start it in the morning, it turns over real slow several times then it starts. The rest of the day it starts fine. Im going crazy trying to figure this out. I cleaned the battery cables and they are tight.
Can someone give some ideas? Im having to wait til funding allows to get it to the Auto electric shop.
Thanks in advance for help and sorry for this looong post

ETsC10 · 10-30-2015, 08:32 PM

Sorry to hear you're having electrical problems!
To get this thread Rollin ' to a fix, I'm m moving it over to the electrical forum.

Good luck,
Ellen

**VetteVet** · 10-30-2015, 10:00 PM

This most often points to a voltage regulator issue. Of course it's in the alternator, before you buy a new alternator try checking all the connections to the alternator including the plug and the wire(s) in it.

With a fully charged battery I would disconnect the alternator wiring and start the car to see if the flickering happens. This would isolate the alternator from the system as a cause.
You most likely will see some codes relating to no charging but they can be reset.

65chevysub · 11-01-2015, 01:27 AM

Thanks for the reply, however the alternator was replaced in February. I'm going to have the battery check tomorrow to see if its going bad. I will post on here what I find out.

65chevysub · 11-02-2015, 06:07 PM

Update: had battery checked and it's bad. Going to get a new one on Thursday then wilk check the flickering light issue.

04-23-2015, 05:29 PM	#1
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	lights flicker upon startups- '04 Blazer I just noticed on our 04 S10 Blazer that the clearance lights flicker for a bit right after starting then it stops. We had the alternator replaced a couple months ago. Any ideas and should I be concerned and have the electrical system tested? Thanks Last edited by ETsC10; 10-30-2015 at 08:42 PM. Reason: Added to title

08-25-2015, 08:05 PM	#2
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	Re: lights flicker upon startup Update on my post. All the lights pulsate for a little while after starting(about5 minutes) then it stops. Could this be a ground issue?

08-25-2015, 09:08 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: lights flicker upon startup Could b a bad ground or just dirty filthey contacts that have not been cleaned and tightened up for years __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-25-2015, 09:32 PM	#4
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	Re: lights flicker upon startup Should I start with the neg cable then check all the lights? All the dash lights and exterior lights are pulsating

10-29-2015, 11:39 AM	#5
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	Re: lights flicker upon startup Maybe someone can give me some advice. Our 04 Blazer LS developed a draining issue. It's been working fine except the flickering lights. The battery seems to be draining overnight, but there is nothing left on. I cleaned the inside on Monday and accidentally rotated the done light switch on. I figured that out and made sure it is off now. When I get in to start it in the morning, it turns over real slow several times then it starts. The rest of the day it starts fine. Im going crazy trying to figure this out. I cleaned the battery cables and they are tight. Can someone give some ideas? Im having to wait til funding allows to get it to the Auto electric shop. Thanks in advance for help and sorry for this looong post

10-30-2015, 08:32 PM	#6
ETsC10 Hand Crafted C-10 Join Date: Aug 2006 Location: Burien, WA Posts: 5,180	Re: lights flicker upon startup Sorry to hear you're having electrical problems! To get this thread Rollin ' to a fix, I'm m moving it over to the electrical forum. Good luck, Ellen __________________ . Forum Guidelines and Rules Buying and Selling Code of Conduct Become a Board Supporter! Truck FAQ Ellen... the boards artsy-fartsy, eclectic, truck-lovin' gal-member...

10-30-2015, 10:00 PM	#7
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,718	Re: lights flicker upon startups- '04 Blazer This most often points to a voltage regulator issue. Of course it's in the alternator, before you buy a new alternator try checking all the connections to the alternator including the plug and the wire(s) in it. With a fully charged battery I would disconnect the alternator wiring and start the car to see if the flickering happens. This would isolate the alternator from the system as a cause. You most likely will see some codes relating to no charging but they can be reset. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

11-01-2015, 01:27 AM	#8
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	Re: lights flicker upon startups- '04 Blazer Thanks for the reply, however the alternator was replaced in February. I'm going to have the battery check tomorrow to see if its going bad. I will post on here what I find out.

11-02-2015, 06:07 PM	#9
65chevysub Registered User Join Date: Feb 2013 Location: Cottonwood, Arizona Posts: 1,382	Re: lights flicker upon startups- '04 Blazer Update: had battery checked and it's bad. Going to get a new one on Thursday then wilk check the flickering light issue.



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