Yes it matters. Sparks may fly. The outside ring of the cigar lighter, the
large part connects to ground / chassis / earth.
For a positive ground / chassis / earth car, this is connected to the plus
side of your battery.
All modern electronics are negative ground.
To make a positive ground car's cigar lighter work you would need to isolate
the entire outside ring and body of it from touching any part of the car's
chassis. This is usually very difficult to avoid and a dangerous set-up if
anyone other than you works on the car.
You see the problem is that 99% of the car is connected to the earth and is
for this reason often called common.
Anything "common" you touch with the cigar lighter body will cause a spark
if to "reverse wire" it.
Sooooooo, take the plunge, convert to negative ground then this problem
goes away. It is easy and has advantages. There are many sources of
information on this conversion, is free, and can be done in an afternoon.
Hope this helps.
From: firstname.lastname@example.org [mailto:email@example.com] On
Behalf Of TimWardUK@aol.com
Sent: Sunday, April 23, 2006 2:32 AM
Subject: Electricals Question
I am thinking of fitting a cigar lighter to my BJ8 so I can charge my
phone, and run a TomTom SatNav off it as well.
My BJ8 has the original wiring set up.
My question is:
for devices that run off a cigar lighter like phone chargers and power
converters for things like SatNav, does it matter whether the car is
Thanks in advance for all the help I know i will get.
12 Mill Road
Northants. NN7 4BB
Tel: 07855 388 751