Weird electrical noise when turned off - transit

[beclawrence007]

Hello,

I have this weird electrical kind of noise coming from this thing next to the engine, see in video. No idea what this part actually is?

And why it is making this noise? there has been water getting in the bonnet so wondering if something electrical is damaged causing this noise
or is it just a normal noise?

happens when turned off, lasts a minute usually then stops

https://www.youtube.com/shorts/_N1FNCfRv6o

thanks for your help
bec

[Airthies]

Try disconnecting the turbo actuator.
Rectangular plastic and metal box with wide flat plug.
Check all relays in the engine fuse box haven't corroded or failed shorted. Pull one at a time to see if noise stops, if it does swap out relay to see if this solves issues.

Sent from my S99 using Tapatalk

[marcrbarker]

It's fascinating how the different makes Bosch/Delphi/Siemens/Denso have their own characteristic sounds. I first heard sounds like this RadioControl models in the 1960s, coming from the servo actuators. I reckon an engine management expert blindfolded could identify what make the system is just by listening under the bonnet(hood stateside) during those 10 seconds or so after the engine is switched off. The sound is a 'pulse-width-modulated' (PWM) vibration that's fed to valves and motors and the like. They use a pulse instead of a silent analogue voltage because digital pulses use cheaper components. Way more complicated but cheaper. They don't have to use an audio range PWM rate, they could make it ultrasonic but I think the designers make the sound audiable because the designer likes to hear his handywork in operation.