May be a stupid question, but I recently passed LGV 2 and am working on agency now driving all sorts.
The thing is that the first wagon I drove through the Agency was a 7 1/2 ton Iveco, I used Sat nav powered through the cigarette lighter, all OK. I also drove a Scania (28 ton, I think) which I used Satnav in, again all OK , only yesterday i was driving a 7 1/2 ton DAF and my mate told me the lighter blew his invertor(he needed a stereo running on the flatbed for a procession in a bank holiday parade, does the voltage out the ■■■ lighter vary from wagon to wagon, if so, how can I tell without spending an hour looking through the vehicle manual (if their is one).
Cheers
I would suggest that it was the amplifier that blew his inverter, not the lighter socket. He was lucky he didn’t set the whole vehicle on fire.
An inverter will normally shut down on a thermal sensor if it is overloaded slightly. I suspect that the thermal sensor didn’t have time to shut down and simply melted. An amp and speakers for P.A. use need a hell of a lot of power.
The voltage will vary with the vehicle. Either 12 or 24 volts, but many items, such as SatNav, phone chargers, electric shavers, will often cope with both voltages. What makes the difference is the Current. Put too many Amps through anything, and it will Fry.
Have a look in the sat nav manual they normally tell you if the power lead will convert 24v to the required volts.
If in doubt get a 24 to 12 dropper. See Here
Putting 24 volts through something that is supposed to run on 12 volts will damage it.
hollywood:
Putting 24 volts through something that is supposed to run on 12 volts will damage it.
Don’r arf boil the kettle quick though 
I mostly drive Scanias and my Satnav, is ok with these, satnav running on PDA, I can run it without external power but battery doesn’t last long. If I am doing long journey I plan route before and only use it when I get to outskirts of town.
Try pulling the lighter out of the socket, and looking to see it is stamped 12v or 24v. The lighter in my FM12 has a tiny 24v stamped on it.