I have an Astra VXR which has the perfect lighter socket. It is always
powered even when the key isn't in and I can turn the engine on and off
without affecting it. This is great becuase I watch my portable dvd
player in the car of a lunchtime and I can put the engine on to warm up
without it reseting. Now i've just had the new corsa on loan for a few
days and that only gave power when the key was in and cut it briefly
when you powered up - causing my dvd to go back to the start. I also
had another car recently that gave it without the key but still cut it
on power up.

So is all this variation due to any reason? like the battery needing
all the power to start the engine for instance?

In article <1169846418.250998.125210 (AT) j27g2000cwj (DOT) googlegroups.com>,
alfi286 says...

--
Conor

The United States, increasing quality by lowering standards since 1776.

alfi286 wrote:
Having the 12V controlled by the key can be good; it stops you leaving
something running that drains your battery and leaves you stranded.
Also, disconnecting the socket whilst cranking not only potentially
gives a bit more power to the starter, but saves anything you've got
plugged in from any nasty spikes that come down the line due to the starter.

Some cars have the facility to change how they control the lighter power
- usually by moving a fuse in the fuse box.

Matt