Team, might sound basic but "what electrics am I running?"

I have a 91 SWB Safari TD42.
The dash electrics show a 24v dial
I have 2 bty in the bay
The engine bay fuzes are 24v
Sooooo... I think I am running 24v, only...

The lighter socket hasn't blown up the GPS or phone charger and the towbar electrics haven't blown up the trailer lights (brought for a car not the mantruck)

Where do I start?

D.