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Practical Wiring - Club Level: Preparing Documentation

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Preparing Documentation


Connection Document, save a local copy to be able to edit.

FD3S Harness Physical Layout

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00:00 - The documentation we prepare to go along with our wiring harness serves two very important functions.
00:06 It allows us to confirm that every connection is accounted for and we know where every wire in our harness needs to run and that we have all the required materials on hand.
00:15 It also gives us a record of how the harness was built.
00:18 So in a year's time when the details have faded from our memory and we want to make another modification to the vehicle, we can refer back and know exactly how the wiring is connected.
00:27 If you're constructing wiring harnesses for other people the documentation you provide should become a point of pride, as it will add a lot of professionalism to your operation.
00:36 Once word gets out that you are thorough and provide detailed documentation it will set you apart and lead to future business.
00:44 Throughout our design process we will have made a couple of quick sketches to help visualise our design and check that it is correct.
00:51 We're now going to bring all this information together into our final documentation which will consist of a spreadsheet document that details every connector on the harness, every pin used, where it makes a connection to.
01:02 It will also detail the wire type and size used to make that connection and how the harness is going to be strain relieved and booted at the connector.
01:11 In practice, this task is often undertaken in parallel with our design steps as documenting our design as we progress through it avoids us having to remember too many details at one time.
01:23 To help with creating this document, we have included below the completed document for our FD3S example and we invite you to use this documentation as you wish, editing it for your own needs.
01:34 This will involve modifying the connector names and types to suit your harness design then adding in the connections and types of wire used, drawing from your quick sketches for this information.
01:45 Any unused pins on a connector should be noted as NC for no connection.
01:50 The documentation is not complete until every pin on every connector has been accounted for and either has a destination or a no connection next to it.
01:59 The second document we prepare is a tidily hand drawn document which details the physical routing and length of the harness sections, including the branch orientations.
02:09 The information for this drawing will largely come from the routing template we've created at the harness routing and branch orientation design step.
02:17 Using a sewing tape measure, determine the lengths of each harness section and begin transferring this design onto paper.
02:22 This drawing will not be to scale but the length of each harness section will be clearly denoted on the drawing.
02:29 Linked below once again is this document as it has been prepared for our FD3S example.
02:34 These two documents should completely define your harness and give anyone working on the vehicle in the future the information they need to know how the wiring is connected.
02:44 The final harness design for our FD3S example is fairly typical of a harness design for a modified street car.
02:51 The ECU and power supply relays are mounted close together with another connector in this location interfacing to the OEM electronics in the vehicle.
03:00 The EFI harness then passes through the fire wall where we will reuse the original grommet to ensure the harness is protected and strain relieved at this point.
03:09 The harness enters the engine bay as a single trunk but shortly branches out to the sensors on the gearbox ignition coils, grounding point, and the water temperature gauge sender.