Living with Sally
The MGB Roadster
This is the original wiring diagram for a 1974 UK MGB
I started looking at this when I realised that most of Sally's wires were NOT fused at all
(Or at least multiple circuits all go to only 4 fuses!)
I also want to add a few relays to take some of the load off the switches
So it seemed the right place to start!

Click to enlarge

There are quite a few changes and additions I want to make to Sally's electrics - in random order:

  • Central Locking
  • Dash mounted ignition switch
  • Later Indicator stalks with horn and wipers etc
  • MP3 capable stereo system
  • Possibly a 'satnav' system built into center console
  • Uprated headlights (maybe HID?)
  • Remote boot release (switch for this in each door)
  • USB charging ports in center console for my phone etc
  • Additional cigarette lighter style auxiliary sockets under dashboard for powering equipment that doesn't use USB.
  • Additional cigarette lighter style auxiliary sockets inside boot for powering equipment that doesn't use USB.
  • TWO 12 volt batteries to replace the original 6 volt ones (in view of all the extra electrical stuff being added)
  • Interchangeable center console panels containing different equipment?? - Not sure about this yet!
  • Electrically Heated Seats
  • Possibly electric windows
  • Auto cancelling overdrive
  • Alarm system (including automatic window close if electric windows fitted)
  • Two fuse blocks under bonnet
  • Additional fuse block in boot
  • Relays for heavy load items
  • Voltmeter?
  • Quick release cabling connectors for easy dashboard removal in the future
  • Under dash (footwell) courtesy lights (LED)
  • In-door 'puddle lights' (under bottom edge of door)
  • LED gauge lighting
  • Ant-Hijack system - cuts ignition if you get car-jacked :)
  • LED lights for boot interior (automatically switched on when boot opens)
  • Switches for heated seats in centre console
  • Swap indicator flasher unit for digital
  • Swap hazard flasher unit for digital


  • I've probably forgotten a lot and will add to this page as I decide to do things


    Found a chap on eBay who has what I need and ordered about £60.00 worth of various sized, differently coloured, cables
    Luckily I didn't need to buy complete rolls of cable as I want so many different colours
    This guy sells them in 5 metre lengths.

    I have ordered the following cable (Hopefully this will do)

    6mm 53amp tri rated - 10m Black - 5M Red

    0.5mm 11amp thin walled - 10x 5m in various colours

    1.0mm 16amp thin walled - 10x 5m in various colours

    I ordered a selection of blue, red & yellow spade crimps at the same time.
    No bullet connectors?
    I hate them and intend to replace most of what is on the car with soldered joints or multi-block connectors

    The spade connectors are mostly for the new fuse block and gauges etc on the dashboard
    If everything goes to plan then I will use multi-block connectors to connect the dashboard wiring to the main loom in the car
    This will mean future dashboard removal should be easier (at least electrically!)


    Ok... I was wrong... I need a LOT more cable

    Once I actually started working out what I want to do and exactly how to do it I realised that I need quite a bit more
    cable in different grades so ordered another £60.00 worth of cable from my favourite guy on eBay