My battery and brake light are on while im driving. No problems starting. I noticed tonight my headlights were getting brighter and dimmer. Could this be the alternator going out? Is there and external voltage regulator and could it cause this problem?

 

Is your belt on there?!?!


Brake and Battery lights on mean no charge!

 

Yea ur charging system sucks. Check n see if the belt is on right. N get ur alt checked.

 

had the same problem about a year ago it was my alternator

 

Headlights getting brighter sounds like a short. Check your alternator wire n make sure it is no copper is touching metal. Had that in one of my old truck. Dimming is you alternator going bad. While you engine is running take off the positive. If the engine dies, it is a bad alternator.

 

My brake and battery light was on ever since my steering ripped all the wires from the alternator. I put everything back and recently changed the alternator. Also checked the brake light swtich and if theres enough fluid everything seems okay. Im running an sr5 cluster and the volt meter seems good started up every single time for the past year but i cant figure out what is it that keeps the lights on.

 

My brake an battery light were on an changed the alt an fixed it

 

Brake light?

Why would the brake light be affected by the altenator? Just wondering.I've only had the battery light come on.

 

They always seem to come on together. Kinda like wen u turn on the truck the brake, battery, n oil light come on then go off real quik

 

Put a new alternator and voltage regulator on. New terminals. The lights are still on.

 

does it struggle to start? like if the battery is low

 

Did you test your old alt. Sounds like you're grounding somewhere. Are all your lights and sh** working.

 

there's a ground wire from the alternator wire bundle, make sure its well grounded too

 

Grd to alt not good enough and is there brake fluid in mat cyl if not is wiring to mas cyl connected or in good condition wires not touching?

 

The brake and battery lights both come on due to a low voltage problem. Check your voltage regulator, charge light relay circuit and ground connections. The diode circuit in the charge light relay circuit could be bad, broken or corroded ground wires or burned / fused 12V positive wiring.

 

Pull the new alt. & have tested! Could be a bad one!
When both lites on, problem with alt.!
Just lost mine ,& it's a stock casing reworked to put out 140amp. Regulator failed causing increase in voltage ,this can burn wiring!!
Going with a 3 wire GM 12SI unit,with mating plug from stock wires to alt. & billet cases.
150amps @ 2,500rpm,& 100 amps @ idle.

 

^Thats whats on mine^