For the first time today I noticed my stereo turning off briefly then coming back on and going through this process repeatedly when out driving.Then I associated or connected the problem with the stepping on the brake and sure enough if I stepped on the brake the stereo would kick off.Then I noticed at a full stop the alternator droppping about two volts in a sudden movement followed by a pulsating movement of the alternator needle in concert with the turn signal.Then when I came home I noticed if I popped up the headlights or turned on the fan or both the alternator would quickly drop down to 6 volts or so then rebound upwards.Are these all the signs of a failing alternator or perhaps something else?

 

You have a short. Check your illumination harness behind the stereo (do you have an aftermarket or a stock?)

 

It is an aftermarket Sony which doesn't require the orange illumination wire and I believe I taped it off so it would mind it's own business.I guess I wil take a look at it if necessary.

 

Run multimeter on the wires to find which one's causing the short. It might be from your 12Volt rubbing against another wire for your brakes. Get ready for an FSM reading.

 

If he turns on the fan and it drops to 6 volts thats his alt is bad and the battery is going too.

 

I just checked to see what would happen to the radio if I ran it using the key in the accesory position(engine off) and it would operate properly even when I depressed on the brake pedal while the voltmeter read 12-12.3 in that range.

 

turn on your lights, turn on the car, push brake, do the lights dim quite a bit?

 

Yes the lights dim quite a bit and the alternator happens to be 8 yrs. old but had stood strong like a trooper with no complaints until earlier today.I will check the fsm to see if there is an easy check to verify whether my alternator is checking out for greener pastures.

 

Does it make sounds when you turn on lights and push brakes? The battery sounds fine

 

As far as "does it make sounds" are you referring to the stereo or perhaps something else? Ok. I just tried to start the car and it acted like it was dead until I stepped down on the brake and it started right up(very strange).I then turned on the headlights and no drop in voltage.Then I tried the fan and also no drop in voltage.Then I tried both fan and lights and no drop in voltage.Tried the pumping of the brakes yet was all well.Sounds like I might have some type of short rather then it being isolated to the alternator itself.Looks like I am in deep doo doo.Oh well! I think I am going to take it for a spin aroung the hood to see how things unfold.At this point anything is possible.I am the original owner and this is by far the worst problem I have had.I guess it was bound to catch up to me at some point in time.

 

I believe I found the problem or it was a "complete" coincidence.Seems that the negative terminal clamp which I had recently replaced was sticking out of the side of the battery box.The piece jutting out was bare metal and I "believe" this bare metal was coming in contact with the underside of the hood thus creating a short! If this is indded the problem then I am a monkeys uncle of immense proportions.This would help to explain why things seemed up to par when the hood was up but not when down.It would be a blessings of sorts if this was ultimately the problem.I will keep my fingers crossed and a big thanks to all who chimed in.The poster who mentioned a short was right on and you know who you are .Thanks again from a fellow board prowler, I mean member.