immax01

So a few days ago on my way home from work, my dash lights and headlights would dim and my radio would reset any time i pressed on the brakes. Also the battery light on the dash would come on for about 1 second. I managed to get home and i checked my voltage while running, it was at 13.4..(normal is 13.5-14.9 from what i understand) so i figured a dying alternator since my cables seemed fine. And these symptoms seemed to me like an Alt. problem.

I replaced the alt with a rebuilt one and drove it around the block for about a mile with no problems. Running voltage was 14.8 and not running was at 12.8. Everything seemed perfect!

This morning i go to drive and immediately the symptoms come back upon braking. The running and not running voltage hasnt changed.. 14.8, 12.8. So it seems that the alt is charging the battery, and the battery has plenty of life in it.. So what could be causing my problems!

I'm thinking that it's a wiring problem somewhere, but im not sure where to start..
I'm so bummed, i thought i fixed the problem, only to confuse myself even further.. Thanks for your help.

***EDIT***
I just read on another car forum that someone fixed this same problem by removing an LED brake bulb. I have an LED bulb for my center brake light. I'm hoping this will work.

Update on post 17..

GS4_Fiend

iTrader: (22)

You must ensure the battery itself is able to past a load test before changing an alternator. Get the battery tested first. If turns out good, check the battery connections see if cables are loose, a very common problem. Check connection on alternator. If all rules out fine, only thing left is a fault battery light indicator has been shorted to ground.

01LEXPL

iTrader: (10)

These cars are known for this.

When replacing bulbs, they need to be all from the same brand, any slight difference in voltage between mixing bulbs triggers the warning, try cleaning the contacts where the bulbs sit, then re-install them.

Too bad you bought the alternator - there was no need... This is common.

The best advice is to ignore it. Since i installed a 3rd brake light [led] from another car, the warning is on permanently. I'm going to remove the bulb from the cluster soon.

GS4_Fiend

iTrader: (22)

Im running LEDs on all of my brake lights i dont have any issues

01LEXPL

iTrader: (10)

mine has been doing that since it was purchased used.

GS4_Fiend

iTrader: (22)

Read my first post. Your problem is one of those.

01LEXPL

iTrader: (10)

^ it's more compliated than that. Not sure how you're running leds, maybe you got a godsend es300. There tons of people that have gotten the light from simply mixing and matching bulb brands - that's how sensitive the light out module is. I'd like to bypass it personally, since it would be less messing about instead of removing the cluster.

I still have to check my grounds and cables. This light was sporadic in my car - now permanent since I have a GM 3rd brake led, in either light mode. Prior to that it would do it at random on the lowbeams mode, since last summer it does it at all times when applying the brakes - but the bulbs are fine...

Hayk

iTrader: (1)

This is a good example of why trying to diagnose an issue over the internet is very difficult. If the OP never mentioned that he modded his car, we would have sent him on the wrong path.

GS4_Fiend

iTrader: (22)

Module? Are you referring to the Brake lamp failure?

pauloil

problem could be with the ground cables or the starter cables. look and where the grounds attach. take them off and clean them with steel wool or something like that. voltage drop test the batt cables. see the attached link to understand the importance of testing the cables under load. I went through 2 alts on my old volvo before i tested and learned the pos cable was bad. you could take off part of the insulation by the connectors and look for oxidation of the cable or feel it after running the car to see if it is warm, indicating increased resistance.

http://www.aa1car.com/library/voltage_drop_testing.htm

pauloil

it not the LED light. those don't require much current, and that is the nice thing about them.

01LEXPL

iTrader: (10)

yeah that thing.

GS4_Fiend

iTrader: (22)

You misunderstood the concept of this thread. OP is reffering to the Battery Light Lamp not Brake lamp. Reread the title.

xsh0tya

I have noticed that my brake light will come on more so due to my driving then anything, hard turning or braking. The ball sensor thing gets caught or somthing and when u hit the thing in the engine (Yea Im very technical) where that brake sensor or ball thing is. The brake light goes off. Your electrical problem aside from that... others can help.

Hayk

iTrader: (1)

Some cars will show a brake light when your brake fluid drops below a certain point. It's supposed to warn you about worn brake pads. The reason you see it during brake applications and turning is because the fluid moves around due to weight transfers.