Electronics

Overview  Even though I am a mechanical engineer, I love to work with wires.  I have had lots and lots of experience with British "Lucas" wiring and pretty much know what color every wire is to pretty much anything in a British Automobile; Scary.  Anyway I decided to try something different with the wires in this, My best project yet.  I decided to retain the original MGB wiring harness.  Yes, the late model MG's had a good harness, The problem was that it was somewhat overloaded and had terrible connections.  So I kept the wires to the lights, ignition switch, heater, etc.. and took the load away.  I did this buy running the original harness through relays.  I made up a new harness that feeds the relays power directly from the battery.  This takes all the current away from the high gauge wires in the OE harness and gives full power to the accessory. 

    The next step in wiring was blending the Land Rover fuel injection harness into the MG's.  This was much easier than it would seem.  The Land Rover's engine harness is a separate system from the rest of the Land Rover except for two plugs that connect the engine to power and a few accessories.  I was able to just wire the plug that came out of the Range Rover into my updated OE MG's wiring harness and after connecting the ignition, battery power, and the speed transducer I was in business.

Fuses  I used the newer style plastic fuses in two separate boxes under the hood.  These fuse boxes came out of the Range Rover and fused the power seats.  My car has ten fuses to date.

Relays  All the relays in my MG were salvaged from the Range Rover.  I used the plugs and relays.  This saved lots of money and the plugs made the wiring look professional.  The relays run the hazard lights, cooling fan, heater fan, fuel pump, EFI, fog lights, head lights and automatic door pop.

Battery  The battery is the same size as the one used in the Range Rover.  I relocated it to the truck because the original battery box was removed when the Jag rear end was installed.  The battery is in a marine abs box and is mounted to the back of the truck.

Alternator  This is one more thing I didn't do buy the book.  I was playing around with where to put the alternator when I found that it would mount using the same bracket the alternator was originally installed on in the Range Rover.  I drilled two holes in the bottom of the bracket and mounted the alternator "upside down".  Then I re-bent the tensioning bracket and mounted it low on the water pump. I did all this so I could use the original alternator that came with the Range Rover.  This took me only about 45 minutes to install.  I was very surprised that this part would be easy.  This also leaves room for an air conditioning compressor I am thinking about adding later.

Starter  Gear reduction starter from www.britishstarters.com

Cruise Control  I added cruise control to my car in February, 2004.  I used an Audiovox unit that I have used on other cars.  The wiring is just as the instructions show except for one tiny detail.  On an MG, or any Lucas car, the brake light switch is run through positive.  This will not work with the cruise control's computer since it is wired for American cars with a negative switch.  What you have to  do is use, again, another relay with two "87" terminals and wire the relay so the brake light switch kicks the ground off for the cruise.