Our o7k swap harnesses are made to run your o7k in any chassis with just hooking up constant power, ignition power, and ground. The harness has its own fuses. They are all made to run with early me7.1 ecus and beetle engine harnesses. Simply plug your beetle engine harness into our adapter harness with the plugs that usually plug into the vehicle firewall. You need both sides of the engine harness. If you plan to run vw/audi alternator you need that sub harness as well. If you plan to use the alternator wiring for your chassis, you don't need that sub harness. If you plan to run a different alternator, that isn't factory to the chassis and being used with the factory cluster, you may need an alternator charging light to wire in for your alternator to charge. With this harness, if you run the vw/ Audi alternator with the vw sub harness, you will not need a charging light with any cluster as it is wired in. All of our harnesses will include the drive by wire pedal plug of your choice, mk4 or mk5. We can also send it with just flying leads with the wires marked if you're running a different drive by wire pedal, or could possible find the appropriate plug for your desired pedal. They also all include an obd port. You can use this for scanning codes as well as gauges if you choose to use an obd gauge solution. If you're wanting to use a factory style gauge cluster, we can include flying leads for vehicle speed sensor and tach signal. We also include wiring for a clutch switch for launch control use with the wires marked. We've used this solution in many chassis from Nissan s chassis, Mazda rx chassis, buggies, etc. Simple and easy. No need to tie into the chassis or existing engine harness of your project. Please send us a message through the contact page, or use the notes section at checkout to give us the details on your project. For example, throttle pedal choice etc.