Editing Rewiring a vehicle

--[[User:Docvette|Doc]] 18:03, 13 September 2006 (PDT)When completely rewiring a vehicle there are a few things that must be determined beforehand. First, one must decide if a prefabricated harness will be used, or if a custom harness will be made from scratch. In any case the harness should be assembled into groups and cut within a reasonable distance to the right length, while leaving extra wire to account for routing. == Scratch Built Harness == ---- If you Intend to Scratch Build your Harness, You will need a few things from the Garage..A pair of Saw Horses, One or (better) Two, 4 X 8 Sheets of 1/4 or 1/2 inch Plywood..Some nails about 4 inches long. If you have a Two Car garage you can afford to tie up for a few days, Set your saw horses up next to the Vehicle to be wired, and join and place your plywood on top of them. You should now have a platform About the size of the Vehicle to be wired. Get a Magic Marker, Draw a rough out line of the Vehicle Side To side, front to tail, with lines for Firewall, Dashboard and trunk spaces on your plywood. Measure and show headlight locations as well as Tail lamp locations. Next, Studying your Vehicle, Determine The Course of Harness routing and areas of location for the Fuse buss, Battery, Dash, Engine Bay Harness, and all locations for electrical plugs and devices..Make a rough drawing and take measurements from point to point. Transpose those over to your plywood, Draw a line to show Routing, and at each Termination point Drive a nail about 1/4 an inch in your wood, and Mark it's function(Tail, Left..Ect..)..Place your plug/Socket and pins there (for later..)Continue until you have all termination points laid out and represented by a Nail on the plywood. That being done..Figure out your Wire gauge for each circuit, as predicated on The Draw and Length of the run..Make a list (EXAMPLE: Tail Lamps...21 Feet...10 amps...14 gauge Black) Now starting with your smallest gauge , at the Buss, Tie the wire there, run it down your marked route line (add Extra length for anywhere it must rise or fall within the body) To the nail marked "Tail lamp" then mark the wire with a wire marker (available at any hardware store) mark the function and number on your notes.. and continue the "Wrap" along to the next Item (like the right lamp ect..) Do not cut until the wire reaches termination.. Continue until all color wire of that gauge are laid out..Then Repeat with the next largest gauge wire, until all wire is laid out nail to Nail..Be sure to keep your runs straight..and tight, and do not cut the nail ends until ALL wires are in place..ADD 5 % "Spares" and mark then as such the length of the harness...(for future expansion or In case you shoot a screw through one and get a bad wire..) Tie the bundle up neatly with proper tie wraps nose to tail.. Cut all nail ends at an equal distance, referring to your notes, and wire markers, as to function and number.. add your firewall connectors/Sockets, fuse buss and devices.. Lastly, using a DVOM or "Ring Box" Ohm or ring the harness out point to point for accuracy..Correct any errors, and you should be ready to fit it to the vehicle. == Tools and Supplies Required == ---- Next one must have the tools and supplies required for the job. Here is what is required: *Wiring harness *Black wire (for grounds) *Wire, Various Colors (Red/White/Green/Brown/Purple/orange/),Various Gauges. *Good quality Wire strippers W/ Depth Gauge *Crimper's *Connectors *Electrical tape *Wire loom *Wire Markers *Adel Clamps *Anti~Chafe *Rubber mating *Pliobond Adhesive *Grommets (Various sizes) *Electricians Putty *Plastic Conduit (Chrome or black Or any color) *Rubberized wiring hooks (may not be needed in some cases) *Tech or Self Drilling Screws. *Star and Lock washers (various sizes) *Sheet metal screws (may not be needed in some cases) *Accurate Wiring diagrams, as well as YOUR Notes and drawings made for the new system to be installed. If soldering: *Good soldering Station (don't use n undersized or non Controlled unit; it will slow things down) *Solder (24 gauge 60/40 is good) *Resin *De~solder Tools, and Braid *heat gun *Shrink tube *Hemostats *Dental Pick *Read [[how to solder electrical connections]] if you are unsure how ---- == Harness Removal == Next, the wiring harness in the vehicle must be removed. A Digital Camera , and Note pad are your best friends here. Photograph EVERYTHING even if you think you won't need it later.. Be sure to label every disconnected or cut wire as to its original location, and as you do this add it's location, colors, gauges and functions to your notepad. Keep the original harness intact as possible and UNPLUG EVERYTHING YOU CAN. Keeping this harness intact can help with understanding of how things were wired in the Original Configuration before the routing of Harness wire. Once that is complete you are ready to begin installation of your new harness. ---- == Installation Of The New Harness == Once you have your wiring harness and your old wires removed, your first step is to install the fuse block. Many fuse blocks connect to the factory bulkhead connector with bolts, in other cases the fuse block may need to be screwed or bolted to the firewall or another secure location. If the Fuse block is a firewall pass through type, SEAL the edges with a GOOD Water, dust and Vapor type sealer, OR electricians Putty. The next step is to begin routing your wires. While doing this keep in mind any sharp areas that may sever a wire, Where ever you encounter such an area, Install Rubber matting, anti~Chafe or a proper Grommet to the area and secure the wires as Securely as possible using a Rubberized Metallic Adel clamp, Tech or Sheetmetal screw and lock washer. This procedure will prevent the wiring from deteriorating from Vibration and stress chafing. Begin by routing your longest wires first and working in a Counter clockwise fashion working back to the center (firewall). Make Notes and drawings That correspond to your routing / wire functions, and any special Items that may require attention. Locate all your remote ground areas, such as Headlight and tail light Buckets, Fuel Sender / Tank Grounds , and any local grounding areas..Clean and Burnish all paint, dirt,and grease from these areas, install a proper ground, using a Star washer, lock washer, Tech or Sheetmetal Screw. Next, Build / Install your ground Buss System. To do that: Run a properly gauged Ground cable (4 gauge or better) from the battery to any handy bolt at or near the starter, From that same bolt get a Battery cable at the parts store, that has two 3/8 ring terminals on each end and attach it there and to the Frame following the shortest run possible. Next get some 10 gauge wire and ring terminals, and run that from your bolt on the block to the Firewall, and another to the Alternator bracket or mount bolt. Next get some Wire Braid, (Electronics store) and install braid from the radiator support to the frame, Fenderwells to frame , hood to firewall, Doors to door posts, gas flap to body, Gas tank to frame , tailgate / Trunk to body. At each point the wire is grounded, Burnish ALL the paint and grease off to bare metal. Use a proper star-washer and lock. Use sheetmetal or Tech screws where no screws are available. When done properly, all the grounds in the buss system should terminate at the same mount point AT or NEAR the starter. Once these wires are routed and secured you can begin attaching the Device wires to their Devices. The following order is recommended tail lights/fuel gauge sender, headlight/horn, engine compartment, interior lights/speakers, power windows and locks, heater and stereo, dashboard. Keep in mind that certain connectors are not easy to find new, therefore in some cases you must solder or crimp an old pigtail onto the new wire. To do that properly, set up your soldering station, Heat shrink gun and tubing, and your other soldering hand tools in the area of work.. Measure the wires From the Device, as well as the wires from the Harness to overlap about 3 inches in each direction. (leave enough wire slack for devices like lamp sockets that must be removed to change a bulb..Etc..) Then Trim and Strip so they will overlap about 3 inches, add shrink tubing to the wire, sliding it FAR enough back so as not to prematurely shrink it with heat from the solder joint..Then Wrap your wire, first clockwise, then counter clockwise until you have a good SECURE mechanical joint (Tug test it..) Trim excess "Whiskers" from it and smooth as well as possible. Then Apply Heat, and Solder to the wire..heat at one end, solder at the other..and solder until it flows from one end to the other, (Do not "Glob" it..It should resemble the wire bare, except be silver..) Inspect your joint..It should cover the bare wire 360 degrees, from insulation to insulation, (insulation should not be burned or charred, if so reduce tip heat) and be bright Silver to be a good joint. If it is a dull gray, you have a "Cold Solder joint" that will corrode, crack and not properly conduct..start the process again using more heat or heating time. If satisfied with your joint, Slide your tubing down over the joint, and using your heat gun, shrink it down to It's proper gauge. Hold the wire Straight until it has cooled or it will take on the "Droop" of the angle it had while cooling. If you need a Pre~Bent joint, hold it at that angle until cool, it will maintain that angle. Continue Soldering the rest of your Device / Harness Connections until complete. Furthermore it is suggested that a maxi fuse is installed rather than a fusible link and while some wiring harness's recommend the main power come off the starter live connection, running the wire straight to the battery can be a better way to go. Such a case would be an off-road vehicle where water or mud could cause problems if the main power wire is connected to the starter.

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