electrical blip through speakers

[devreeze]

i have a 2002 v70 2.4 auto, and since ive had it, its had a strange electric blip sound through the speakers when i use the brakes, its almost like theres not enough power to cope with braking and having the radio on, also i have been through a fair amount of bulbs this year, does anyone know what this could be, thinking of taking it to auto electrician. thanks

[cornclose]

Sounds like it might be a static problem. Either that, or it's because it's an auto. They're more trouble than they're worth...

[JimmyBurnWorld]

You say you've got through a fair number of bulbs this year. Are we talking all kinds of bulbs or just your brake light bulbs?

If it's not just your brake light bulbs, I would check to see if your alternator is overcharging. If you were just 1.5v over, then you're putting approx 10% more energy through the bulb, this will significantly reduce bulb life.

What conditions do you get your 'Brake Blip' through the speakers? Is it every time you brake, or only when you have certain things running i.e: Climate control, headlights, wipers etc.

If you were overvolting with a sick alternator, putting the brakes on could cause enough of a volt drop through the brake lights to cause noise in the radio (the radio has it's own power regulation, which makes sure all the sensitive electronics get their 3.3V, 5V, etc).

You would probably notice a similar effect if you set your hazards flashing (assuming you can hear the noise on the speakers over the ticking of the indicators).

Get a volt meter and check accross your battery +ve & -ve with the engine running (let it run for 5 mins to recover energy lost from starting, or even better check it at idle after a run).

14.4V is about the most you want to be seeing.

[cornclose]

Either that, or it's because it's an auto. They're more trouble than they're worth...

I'd just like to add that the above has nothing to do with the original question, and the statement is not true. It was a joke as a result of another thread. I'll get me coat...