On 27/12/2014 13:39, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

Presumably you are talking about striplights? I think they usually have
an inverter of some sort in the mount.

Maybe going off topic, you can buy CFLs with standard bayonet or ES caps
which run straight off 12 volt DC. The electronics is all built into the
cap and they are pretty efficient. (I use these off 12 batteries in a
stables and get much better battery life than I did from a 240 volt
setup with an inverter). You do have to get the polarity right but they
don't "blow" if fitted the wrong way.