DIY Network

Mobile A/V System: Drop-Down LCD Monitor From "Weekend Mechanic" episode WKM-311

The minivan A/V system includes a DVD player and this drop-down LCD screen.

In this segment of DIY's Weekend Mechanic, host Bruce Bonebrake installs and wires a 7-inch drop-down LCD screen that's part of an A/V system for a minivan. The LCD screen (and an additional one in the back) will later be connected to a DVD player.

Materials:

In addition to standard auto-mechanic's tools (wrenches, ratchets, extenders, screwdrivers, nut-drivers, torque wrench, etc.) and the installation kits, some of the specialty tools used in this episode included cordless drill, wire cutters and strippers, utility knife and wire hook. An air-compressor and set of pneumatic tools will is optional, but may be very helpful for this project.

DIY Difficulty Rating for the Project: This job requires some wiring and soldering, but the installations are all fairly straightforward and not unlike installing a home stereo-system. We gave it a difficulty rating of 2 on a 5-point intermediate-level scale. It took us about 8 hours to finish this job. Depending on the system you choose and your vehicle, your work time could vary. Allow yourself a full weekend to complete this project properly.

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Figure A

Pull-Down LCD Monitor

• With the prep-work complete, as described in the previous segment, you can now place the metal mounting plate (included in the kit) against the headliner and marking the outline of the location (figure A).
  

• It's a good idea to place foam weather-stripping on the back side of the 1/2-inch plywood mounting board (figure B) to help ensure that it fits tightly and to prevent rattling once the screen is installed. We used 1/4-inch foam strips.

• After peeling the covering off the strip adhesive, slide the board into position, above the headliner, foam-side up. Place the board by passing it through the opening for the console well (figure C). Make certain that the front edge of the board is just in front of the leading edge of the mount.

  Figure B

  Figure C

  
  

• Position the mounting plate according to your marks, and secure it to the plywood board with four 3/8-inch wood screws. (For our installation, we installed the screws in the mounting slots -- rather than the mounting holes -- in the mounting plate.)

• Once the plate has been mounted securely, use a utility knife to cut and enlarge the hole in the headliner that will be used to run the wiring harness (figure D).

• The drop-down monitor can now be installed. Drop the monitor down to expose the mounting panel, pass the wiring harness through the hole you cut in the headliner, and position the panel on the mounting plate (figure E).

  Figure D

  Figure E

  
  

• With the panel in position, secure it to the plate with the screws provided in the kit (figure F). Once the unit has been secured to the ceiling, work can begin on the wiring. Follow the manufacturer's instructions for wiring your monitor. The steps for our wiring are summarized below.

• Connect the A/V pigtail cable using its special connector. The cable serves to extend length of the monitor's video, audio and screen-power leads (figure G).

  Figure F

  Figure G

  
  

  	Figure H
  	Figure I

• Next, extend the length of the ground wire (for the lights in the LCD panel) by crimping on some extra wire (figure H). Also extend the power wire for the lights and the accessory wire that turns the lights on and off. We connected the wire ends using 18-gauge butt connectors -- to match the wire size. We made certain to match the colors of the connectors and wire extensions with the existing wires to ensure proper connection. We then taped the wires together using electrical tape, and cut them to length to make them easier to manage. Enough wire should be left to extend around the overhead console and still reach the courtesy-light wiring harness.

• The three wires should then be routed to the overhead courtesy-light wiring harness. There they should be spliced into the existing courtesy-light circuit, following the manufacturer's instructions. We carefully cut away the sheath on the existing wire harness and splice into each wire and the corresponding wires of our LCD courtesy lights.

• Strip the ends of the existing and new ground wires and splice the two together using an 18-gauge butt connector and crimping tool. Repeat the process for the accessory wire that turns the light on and off when the door is open. Finally, repeat the process for the 12-volt power wire. Once you've crimped the individual connectors for each wire, pull both ends of each wire to ensure that the connection is solid.

• Once all three splices have been made (figure I), wrap all three splices with automotive electrical tape to protect the harness.

• Important: Use a volt-meter, wire-locator guide or test-light to locate which wires are power, ground and accessory.

• Important: If you opt to solder these connections rather than use butt connectors, use extreme caution to avoid burning the headliner fabric.
  

  	Figure J
  	Figure K

• With the courtesy light connected, you can check to make sure that the light is working properly (figure J).

• For our LCD monitor, there was also an additional orange wire that connects to the vehicle ignition that supplies power to the LCD monitor screen so that the screen is on only when the ignition is turned on. Using the same crimping technique as with the other connections, extend the orange accessory wire.

  Once the wiring is complete, and the unit has been tested for proper operation, wrap the A/V pigtail an accessory wire with tape, and route the wrapped wiring across the headliner and down the roof pillar (figure K) and underneath the passenger seat -- where it can later be connected to the DVD player.

  Important: When routing the wiring harness, be certain to keep it away from the seatbelt mechanism so that it doesn't effect the seatbelt operation.
  

Safety Alert: As a standard safety precaution, always disconnect the vehicle's negative battery cable before you begin work on any electrical or mechanical components.

RESOURCES :

The Complete Idiot's Guide to Trouble-Free Car Care
Author: Dan Ramsey
ISBN: 0028635833
Alpha Books

Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896