xrapidx

Hi Guys

I've tried searching... can't find anything similiar t

Starting yesterday, my brake light and alternator (battery) light have started coming on intermittently, but at the same time - any clue as to what is causing this, does the combination mean something, or could it be a short or something?

Here's a pic of the lights just to avoid confusion.

slicksam

usually a sign that the alternator needs to be replaced. When those lights come on the dash, your car is running off the battery and your alternator is not charging.

you should not wait to get that fixed!

xrapidx

Yeh - I was thinking it has something to do with the alternator - it seems to go away under higher revs.

Is it normal for the brake light to come on as well?

Also - what's worst case scenario if it is the alternator and I don't get it fixed now? Flat battery? I'll book my car in, but it usually takes a week or so to get a spot.

Billman250

Start with the battery light.

Dont worry about the brake light right now. Just make sure your brake fluid is not empty, and your parking brake is not on.

Check the voltage with the car running, see if it's charging.

xrapidx

A week later - I've had the car looked at by two different people - neither know what the problem is.

Battery is charging, brakes are fine.

The lights are now continuously on when I switch the car on, when I rev high, say above 5000rpm they both go off... (the point at which they go off shifts).

I've also tried resetting the ECU...anyone have any ideas where to start?

Billman250

Possible bad rectifier. Its inside the alternator.

xrapidx

Will that also cause the brake light to come on though? That's the one thing that's confusing the guys over here... how both lights come on at the same time.

Is there anyway to check the rectifier?

secUnd3r

I had the same problem with an old toyota camry. Replaced the alternator, and that fixed the problem for a few months. Eventually it came back, and found that there was a washer causing high resistance under one of the terminals attached to the alternator. After removing that washer, the problem went away.

Basically, something in the system caused resistance in the transmission of electricity between the battery and alternator. When the resistance was higher than alternator output, it caused those lights to come on.

You are probably going to have to replace the alternator, but it may not be the root of the problem. Check the battery terminals for corrosion, and also the other points of contact for the cars electrical system, grounds and such.

SLracer

Sounds like a loose connection to me. My Saturn was doing this once and I went to replace the alternator and realized one of the nuts had worked its way loose. Tightened it up and after a week of driving around and not seeing it again I returned the alternator. Its at least a place to start, if everything seems tight then alternator sounds like the next logical step.

xrapidx

Looks like it was the alternator.... was driving home last night and the dash rev counter died, then the EPS light came on then the ABS light, then the car just died and wouldn't start up.

fortunately I was only 1.5miles from home - so was able to fetch me other vehicle and charge the battery enough to get me home (took three charges).

Guess its time to start looking for a new alternator.