I could be wrong, but I think Cessna changed the size of the cigarette
lighter plug strictly because so many people were plugging their 12 volt
equipment into the 24 volt aircraft supply and blowing the supply up.

CAUTION. Cessna changed to a 24 volt system sometime in the late 70s/early
80s.

Jim



wrote in message
ups.com...
I've been flying for 7 years now, and a few weeks ago I attempted to
plug in my portable GPS unit into a 2003 172 and ... I couldn't. The
"standard" cigarette adapter has been replaced with a smaller
something. I didn't have time to look too closely as to what the new
outlet is. The GPS was just a backup and I was just going locally .

If anyone else has experienced this, I would appreciate any info on
what adapter I would need to continue to use the "old" cigarette size
plug and who sells them.

Thanks in advance.