Loud noise from car when powered off and locked

Hi all,

When driving, and when the car is off and locked up, I hear a tinny beeping noise from the left rear lights, occasionally also a noise like a fan trying to start but failing.

I've tried pulling various fuses, but the noise persists. If I start the car to stops, but does sometimes reappear when driving. If sit in the car and turn off the car it usually starts the beeping noise again.

The noise is loud enough to be heard inside the house.

Any ideas? The only recent issue was the missus was in the car with the heating on etc, and drained the battery to zero. Had to get a jump start to get going again. When the battery dies the wipers, rear and front wouldn't stop moving, even though they were slowing down. Eveything seems to work okay now, just this annoying beeping.

No idea about the beeping, but the "fan starting up" is probably the pump for the power brakes.

jaapv said:

No idea about the beeping, but the "fan starting up" is probably the pump for the power brakes.

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When the car is off and locked?

What is the voltage of the 12v battery? Could be the aux battery is faulty giving a low voltage causing odd things to happen.

anko said:

jaapv said:

No idea about the beeping, but the "fan starting up" is probably the pump for the power brakes.

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When the car is off and locked?

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My brake pump certainly runs after the engine is powered off - not sure about while it is "locked" - I don't think I've ever got out and locked sufficiently quickly to detect that.

is the car plugged in and charging while its locked and your hearing these noises? if so, it could be the on board charger cooling doing its thing. it will make noises, and pump coolant through to the front radiator while its charging.

Brake pump? Whats one of those? Mine doesn't have one!

Gilbo said:

Brake pump? Whats one of those? Mine doesn't have one!

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:lol: Yes you do

On traditional ICE cars this would run off the fanbelt, for an EV it has to be an electric pump. It is quite a distinctive 'burrr' noise that increases in pitch as pressure is increased.

SolarBoy said:

Gilbo said:

Brake pump? Whats one of those? Mine doesn't have one!

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:lol: Yes you do

On traditional ICE cars this would run off the fanbelt, for an EV it has to be an electric pump. It is quite a distinctive 'burrr' noise that increases in pitch as pressure is increased.

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Or it would use the engine vacuum.

Vacuum is all electric, with an electric pump, and a vacuum tank in the inner right side front guard.

https://youtu.be/uqIWeBDTGm0

big plastic vacuum tank.

Thanks for the suggestions, I've more info on what seems to trigger it.

So sometimes the buzzing noise is in sync with either the indicators being on, or the brake being pressed. I had a Landrover before and when you towed it would give a similar noise to indicate that the external caravan was indicating. It seems to be related. I did have a towbar fitted when in bought the vehicle new (I assume it was factory fitted, but it is a lease car).

The noise seemed to trigger if the main headlights where in Auto, putting them onto full on and the noise stopped, but then when I turn off the car and lock up, the noise returned.

Currently it seems to have stopped altogether!

A mystery, I thought maybe the towbar electrics where damaged or shorting, can't see any damage, but I haven't dug any further.

Ahh for the brake servo - I get it now.. That pic on the previous page also explains why it takes the washer fluid forwever to defrost!!