Hi all,

yesterday I got into my car, started it up and when I dropped the ebrake my drl flickered and the brake light and battery light came on...and stayed on. I was able to fix the problem by turning the car off and then back on, but today when I was driving, the brake light and battery light came on and stayed on. Even when I turn the car off and back on the brake and battery lights will come back on shortly thereafter. I also noticed that my drl are not working now. I've checked all the fuses and wires that I can find, but the problem still persists. Can anyone offer some help?

Thx

 

possibly the switch in the center console for the e-brake.

had a problem with a nissan back in the day and it kept killing my battery and leaving my tail lights on. Turned out to be the brake lamp switch on the brake pedal itself.

 

i'll take apart the center console and see if i can find the switch

 

If the battery light is coming on you have an electrical issue with the battery or alternator, so you need to check those. Could be a weak battery, bad alternator, or slipping belt.
The DRLs going off are just a side effect of this because of the brake light being on. When that circuit is closed the DRL module thinks the e-brake is up and turns the DRLs off.

 

so i was driving the car home from work today and at first the brake and batter lights were off. then as i drove they started to flicker and eventually they were constantly on. by playing around with different things i was able to narrow down that it must be a lose connection somewhere, probably in the engine compartment. if i have the ebrake down, my foot off the brake and everything electrical in the car off then the lights will flicker. turning any one of the following things on will make the lights go steady: parking lights, flashers, stepping on brake, lights, fan heat/cool, ebrake. so it is definitely an electrical problem, and i'm leaning towards a lose connection somewhere. are all of these systems on one major circuit somehow?

 

If it's a bad connection it's one of the main power or ground connections, start with the battery terminals (make sure they are clean and tight, look inside as they can corrode between the terminal and post), then check the main grounds to the frame and engine.
You may also have a bad battery or alternator, connect a voltmeter across the battery terminals and check the voltage with the car off (should be 12.5) and running (should be 13.5-14.5). It's also possible for the alternator to fail in a manner that will still show good voltage but cause symptoms such as yours. If necessary a shop can perform a more complete diagnostic using a scope.

 

yea i checked the battery terminal connections, but i am going to put a voltmeter to it tomorrow. i had my fuel lines replaced earlier this week because of fuel odor in the passenger compartment and i know they disconnected the battery and probably other connections (because my radio stations were all gone). so i'm thinking somewhere something got loose. i'll hunt around tomorrow and let you know if i find anything. in the mean time any other suggestions will be appreciated.

 

so just an update on my progres...

it looks like i solved the loose connection problem. apparently Stohlman Subaru does shoddy work when they replace fuel lines because the main connector to my alternator (the wire at the top of the alternator under the red rubber cap) was completely loose. I tightened it down with a wrench and my problems are solved...no more brake/battery lights! my drl work fine also. my only concern now is that i think with it being loose and wobbling around it was creating sparks and it seems that the inside of the cap is burned. i hope nothing was damaged and my car doesn't catch on fire ;-).

 

With the high current that passes through that wire it's not surprising if there was some arcing due to the loose connection. Probably didn't do any lasting damage but it would be a good idea to clean it up as much as possible to remove the carbon traces as they are conductive.

 

i cleaned it up and it seems to be working fine now. i'm suprised my battery kept a charge for the 3 days it was going on. you are right the arcing caused a carbon buildup and it was worrying me because it was causing smoke, but after i cleaned it up all is well. thanks for all your help!

 

Glad you found it, you might want to let your dealer know what idiots they are and that you won't be returning there for any more service.

 

So just an update to this thread....
After I found the loose connection to the alternator and reconnected it I thought everything was fine. Two weeks later, the battery/brake light came back on. After reading the Impreza Repair Manual and wiring diagrams it turns out these lights come on when the charging system loop is broken. In my case, the connector to the alternator was loose again. I immediately drove it to my dealer and upon further inspection noticed that the wiring connected to the alternator was beginning to melt, which caused the rubber under the nut to melt, loosening the connection.

At first, the head mechanic tried to tell me that this was a problem that had developed over time, but I knew otherwise and insisted on speaking with the Subaru service manager. Unfortunately, he was on vacation for 2 days, but I made an appointment for the day he returned. While I waited, I did some exhaustive research on how alternators function (nice electrical engineering refresher) and it turns out by having a loose connection during those first few days damaged the alternator. The reason for this is that each time the connection was made and then broken it first caused a voltage increase and then subsequently a voltage drop which caused the diodes to work harder and then current to flow in reverse against the diodes. In the brief period it was loose it caused enough damage that it damaged the diodes inside the alternator and possibly the voltage regulator. This caused the remaining diodes within the alternator to have to work harder to maintain the voltage, causing the alternator to get hot and subsequently melt the wiriing.

Long story short, when I finally spoke to the service manager and reminded him that I called him immediately when I noticed the problem (he remembered my call, but did not return it), he conceded that a loose alternator connection can cause damage. I ended up with a new alternator and new wiring. Let's hope nothing else electrical was damaged.

So for anyone having the battery/brake light come on, I would suggest immediately stopping and having it towed to the nearest dealer, so that you don't damage your alternator, or other electrical components in your car.

 

Good to see you got a positive resolution from the dealer. The fact that you did your research and presented a sensible argument instead of just getting upset has a lot to do with it. I give you credit for going about it the right way.

 

I have a reccurring issue with the Brake Light staying on when there's cold weather. If I move backward and hit the brakes, the light goes out. But then when I go forward the light goes back on. Sometimes if the light has been off for a bit, if I get on it (accelerate quickly) the light will come on.

My brakes have always seemed to shift, almost as if the "piston" part of the caliper is moving in the stationary part. The Brake light problem definately seems to be in the brake cable of switch.

Has anyone experienced this problem and found anything wrong with the mechanical parts of the P-brake. Just looking at the components, I can't see what would be wrong with it.

Ray