2010 Kia Rio 2nd Gen, Headlamp height adjuster fault

Hi all, new here so apologies if I've missed any posting guidelines, I did look.

My 2010 Kia Rio 1.4 petrol has a problem with the electric headlamp height adjusters.
Occasionally (especially when it's wet) I can hear the headlamp adjustment motor fidgeting, moving the lights up and down as if I were moving the adjuster switch/wheel on the dash. When parked behind another car, I can see the beam twitching up and down. There don't appear to be any problems with the numbered switch/wheel on the dash which controls the adjuster motors, so I'm assuming it's a short somewhere further down.

Can someone tell me (and maybe show a picture of) where the adjustment motors and/or associated wiring are so I can look for any obvious signs of corrosion? Couldn't find any info about it on Google.

Thanks in advance for your time.

Kind regards,
Chris D
2010 Kia Rio 1.4 petrol 2nd Generation, South East England