2000 Impala lights dim when hitting brakes - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Chevrolet When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 11-26-2013, 12:23 AM   #1
certified crazy person
Certified GM nut
Thread Starter
 
eltatertoto's Avatar
 
Join Date: Sep 2010
Location: hobart indiana (1 hr from chicago)
Posts: 1,871
Thanked 64 Times in 52 Posts
eltatertoto is a jewel in the rougheltatertoto is a jewel in the rougheltatertoto is a jewel in the rougheltatertoto is a jewel in the rough
Default 2000 Impala lights dim when hitting brakes

i drove to my grandmothers and discovered i either have a dropped cell in my battery, a bad alternator or a bad ground. im guessing its a bad ground. every time i hit the brakes, all the lights dim for a second and every time i hit lock or unloak with the car off all the lights dim. also, if you hold the window up button, the car dips to 11V even if its running. then about 10 seconds later its right back up to 14.
eltatertoto is offline   Reply With Quote
Old 11-26-2013, 12:55 AM   #2
Retired Administrator

True Car Nut
 
GunsOfNavarone's Avatar
 
Join Date: Apr 2009
Location: Williamsport, PA
Posts: 2,854
Thanked 167 Times in 129 Posts
GunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud of
Default

Thread moved to Chevrolet section for better viewing.

I'm guessing more towards alternator. Seems when under load and low idle the alternator is not able to output enough amps. Battery should not be much of a factor with car running. Bad ground should cause additional issues at times other than when under load, like when hitting a bump, etc.
GunsOfNavarone is offline   Reply With Quote
Old 11-26-2013, 07:32 AM   #3
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

corroded grounds can seem just like bad battery sometimes. thats why i always start cheap and clean them, if no change then move to the alt. alot of times they last about the same amount of time though i have had to replace both within a few months on a ton of cars, i think the alt may under charge the battery and they dont like that.
jwfirebird is offline   Reply With Quote
Old 11-26-2013, 09:11 PM   #4
Senior Member

True Car Nut
 
WilliamE's Avatar
 
Join Date: Jun 2011
Location: VA
Posts: 3,087
Thanked 418 Times in 376 Posts
WilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond repute
Default

I think Michael is right, at low speeds the alternator is not supplying as much of a charge back to the battery, I am pretty sure when you are idling at or below 800 RPM'* the car starts to pull more from the battery, which sounds like what you are seeing.
I have always had my lights dim a little bit when braking, and when rolling a window up or down.

The only possible way I can think of to try to solve this is to upgrade the big 3 wires, and then maybe upgrade the alternator, clean the grounds while at it like Jusin suggested.
Here is a thread where Art did his wiring, and got the alternator upgraded.
https://www.gmforum.com/buick-172/al...please-305375/

Getting an AGM battery may help a bit also, forgot about that.
ODYSSEY Batteries
WilliamE is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Headlights Dim when Brakes Applied bobinyelm 1992-1999 2 02-27-2014 10:26 AM
Do your lights dim at idle? petraman General GM Chat 18 03-09-2007 10:04 AM
Lights dim and recover shortly after starting Rush Fan Bonneville GXP/ Northstar Powered Cars 21 01-22-2007 07:28 PM
dim lights sse for me 1992-1999 2 10-08-2004 03:42 PM
Brakes Brakes Brakes Terran 2000-2005 11 04-27-2003 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:36 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.