Charging car battery

[Reg]

My tow-car spends most of its life in the garage and I like to keep the battery charge regularly. At the moment I have to move the car out on to the drive to gain access to the battery. The cigarette lighter socket is only active when the ignition is on so I am looking to charge it through the towbar socket.

I have searched on the web and cannot decide which pins I should use. I am assuming that the 12v is direct from the car battery on the grey socket i.e. it doesn't go through a relay or ignition.

 

[JTQ]

I have much the same access problem and leave my Land Rover on a smart charger via the 12S socket

Pin 4 is the positive and pin 3 is the negative.

 

[JTQ]

I have much the same access problem and leave my Land Rover on a smart charger via the 12S socket

Pin 4 is the positive and pin 3 is the negative.

http://homepage.ntlworld.com/mark1968/Towing%20&%20Wiring.htm

This link gives the wiring

 

[Reg]

I was trying to measure for 12v on the grey socket but couldn't get a 12v reading. Just changed the battery on the meter and now I get the 12v I was looking for on pins 3 and 4 like you said.

I was concerned that it might be going through a relay or something.

Many thanks

PS

Link is very helpful.