Headlamp movement control

Anyone know how to fix headlamp movement control on a 728i
Is there a motor or solenoid that may have gone ? Both ligths are affected so it may be electrical

Logikman

What year 728i? I have some electrical data but not for all years. Also, are you saying the headlights work but the alignment is wrong??

Its a late 1998 s reg.
The problem appears to be the electricaly controlled
arms that adjust the beam angles when are towing
or carrying heavy laods in the boot. For some reason
they have both stopped working when the dashboard
control wheel is turned

Sorry, my electrical data won't help. I don't even list a 728i. Perhaps it's a model that wasn't sold in the US and I see you're in the UK. The diagrams for an 88 735i, the closest car I have to yours, doesn't show any sort of motor associated with the headlights at all.

I assume you've checked the fuses. Also note that on US cars some of fuses are under the back seat in the rear power distribution box.