Brake warning light on when key on acc, off when engine on

[Mike_GST]

I did A LOT of research, some tests, multimeter readings and I can't find what is wrong.
That same light that comes on when you pull the handbrake (emergency brake), is lighting up when I turn the key to ACC position, doesn't matter if the handbrake is pulled or released. All the cases I read until now, the light stays on when the engine is fired up. The wierd thing is that in my case, the brake warning light turns off after engine's on. Although the car works ok, I'm really woried that this could be symptom of something bad about to happen if I just let it go.
Battery holds 12,6 volts, must be ok.
My alternator seems working fine too, 14,4 volts with no load and 12,4 volts with EVERYTHING on.
Unpluged the handbrake switch and the brake fluid level switch and nothing changed. Took a look at the electrical diagram and there is nothing else that would trigger this light on. The only test that shut it off was when I pulled the 10A fuse from the position 8 of that box under the dash (gauge related).
I checked all the fuses, they're all good.
Fluid level is at the MAX line.
Other thing I could notice is that when the key is on ACC position, the warning light gets brigther if I pull the handbrake.
The issue started when I replaced the hazard/turn signal relay, which by the way, I already unpluged and nothing changed.
Please, give me some ideas!

 

[TSiAWD666]

It's supposed to be on. I believe it's tied into the alternator light's circuit, and that will be on since the alternator is not running, and thus the brake light will be on too. The idea for this being on unless the car is running and the tests check out is, I believe, is to provide a dummy light test for the dash cluster.

 

[Wilsonf4i]

I'll 2nd that. It's supposed to be before ignition. It's like that on all cars even my bike.

 

[2G@wD]

Ok, my brake light is staying on, fluid ok, new brakes, bleed the lines...idk what to do?

 

[EC17PSE]

Exactly as above, that oil light and engine light come on, once the key is turned all go out unless you have a fault, only if your alternator go's bad could the brake light come back on, its just how the system is hooked up, do not fear

 

[PlanZero]

The OP says this didn't happen until he replaced the relay. What was it doing before? Not working at all?

If your dash brake light stays on, the first thing to check is the switch under the cup holder. Kind of like when your rear brake lights stay on, it's usually the switch under the pedal.

 

[Mike_GST]

PlanZero and Wilsonf4i before I started messing with the hazard relay, the brake warning light went on only when the handbrake was pulled, whenever key on ACC position or ON (engine working). As far as I remember, all cars work this way. I checked the handbrake and the fluid level switches and they are ok, the problem shouldn't be them.

TsiAWD666 and Ec17pse I'm getting suspicious about the alternator. I'm kind of new on electrical stuff, but what if there is a diode burned out on the diode plate of the alternador? Could that somehow send a reverse current (or ground) to the brake light circuit and trigger it on? Is there a DIY to check all the way the alternador?

Tonight I will unplug the alternator just to see what happens.

Edit: where I wrote "brake light", I wanted to mean "brake warning light".

 

[91talonts1]

I thought all the dash lights come on with the key and go off with the engine, so you know if there's a bulb burnt out.

 

[PlanZero]

Well when your alternator's on it's way out the battery and brake light will come on and usually go off when you rev it up a little, then they'll just stay on until the alternator dies, so you may be on to something. Not sure if you still have the stock alternator, if so it may not be a bad idea to upgrade to the 90 amp galant alt.

 

[Mike_GST]

Ok, the issue is related to the alternator. I unpluged it yesterday and the brake warning light went back on its regular working again. It just lighted if the hand brake was pulled or if I push the brake fluid reservoir float down.
Next step: disassemble it, clean it and test it on a bench. Maybe the problem is a preaty cheap internal component to replace.
PlanZero just in case, whats the OEM code for the Galant 90amp. Is it a plug and play mod or would I need to adapt it somehow?

 

[PlanZero]

I don't know the OEM number for the galant alternator, but yes it's plug and play. I grabbed one from the junkyard and took it to the local parts store to have it tested.
Actually, I just remembered last time I bought an alternator from the parts store (advanced auto, NAPA, auto zone, not sure what you guys have down there) they had the 90 amp option listed under eclipse/talon. This is for Canadian models which require daytime running lights.
If not just order it from rock auto.com, if they even deliver to Brazil.

 

[Mike_GST]

Just before start openning up the alternador, I gave a try on checking those three diodes on the gauge instrument cluster plate, right on the trails between brake, charging system and oil pressure warnings.
Still no donut! They're fine.

 

[91talonts1]

I'm having trouble following what you're trying to diagnose here. If it's just that your park brake warning light is on in the acc position regardless of park brake position, that's normal. I checked my talon and two other 2g's all 3 stayed on until the engine was started.

 

[Mike_GST]

I'm having trouble following what you're trying to diagnose here. If it's just that your park brake warning light is on in the acc position regardless of park brake position, that's normal. I checked my talon and two other 2g's all 3 stayed on until the engine was started.

I'm getting embarassed on this! I have this car three years and blows my mind I've never noticed that. All the cars I drove, I can't remember it working like this. Just don't make sense. Would you care of making a short movie of you car dash warning lights during the engine start procedure? Sorry, but I'm freaking out.

 

[91talonts1]

I'm getting embarassed on this! I have this car three years and blows my mind I've never noticed that. All the cars I drove, I can't remember it working like this. Just don't make sense. Would you care of making a short movie of you car dash warning lights during the engine start procedure? Sorry, but I'm freaking out.

Sure as soon as I get a chance. The reason the brake light and the other instrument lights turn on with the key and then go off, is so you can easily tell when a bulb is out.

 

[Mike_GST]

Sure as soon as I get a chance. The reason the brake light and the other instrument lights turn on with the key and then go off, is so you can easily tell when a bulb is out.

Thanks 91talonts1, but yesterday I took a time watching lots of videos in youtube. Also did something that suppouse to be the first thing to do: read the manual Turns out you guys are right. This damn bulb really lights up when key on ACC position, whenever e-brake up or down, and lights out after engine starts Keeps on if e-brake is up or brake fluid level low. Also if the alternator is in the way to die, the charging and brake warning bulbs keep on toghether after engine starts (I read this somewhere). If brake and charging warning lights don't light up togheter when ACC position (e-brake down), probably the alternator is unplugged. If charging warning light stays on after engine start, probably the belt came off the alternator pulley.

I vote this the most useless thread ever!
Maybe in US this is the normal warning lights protocol, but here all the cars I remember to drive, that bulb should never light up on ACC position unless e-brake engaged or there's a fault.

Well, so I conclude my tail lights convertion from JDM (blinkers separated from brake) to USDM (both togheter) worked like a charm and I didn't ruin anything

Thanks.

 

[David Prather]

hey you all my name is david and I am new to dsmtuners.com as I resently bought my first dsm. I have been going through this car with a fine tooth comb fixing things that needed fixing before putting it on the road. I need someone elses help with one problem. my dash lights don't work. ive already taken out the instrument cluster and installed new blue leds( I also sanded down the back side of the instrument templates and made sure they were calibrated when I re-installed them). but still no power. I'm wondering if there is a main relay? or could it be a bad dimmer switch? something else? thanks ahead.