DIY Network

Remote Car-Start System: Wiring, Part 2 From "Weekend Mechanic" episode WKM-301

In this segment, Weekend Mechanic host Bruce Bonebrake continues with the wiring for the remote car-start system with identification and connection of the remaining wires and connection to the power door-locks. The system allows a remote-control transmitter to start the vehicle, lock and unlock the doors and turn on the heater or a/c.

DIY Difficulty Rating for This Project: This job is relatively advanced and should only be undertaken by experienced automotive DIY'ers with some knowledge of automotive electrical systems. We gave it a difficulty rating of 5 on a 5-point intermediate-level scale. Installing the kit on our project vehicle took about 8 hours over a period of 2 days. Installation time may vary according to specific vehicles or the type of kit or options selected.

Important:Altering your car's automotive electronics must be done very carefully or serious damage could result. If installed incorrectly, the device could prevent your car from starting, or could even shut off the car during driving. Every electrical connection in the installation procedure must be made correctly. If you're not comfortable doing electrical work on your car, have this type of unit installed by a professional mechanic.

Important: Included below are the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most vehicles. With any particular vehicle, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of repair-kit you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.

Materials:

Standard mechanic's tools (wrenches, ratchets, extenders, screwdrivers, nut-drivers, etc.)
Remote car-start system kit
Soldering gun and solder
Electrical tape
Plastic wire-ties
Heat-shrink tubing
Heat gun
Digital volt-ohm meter
Test light
Wire cutters, strippers and crimpers

Safety Alert: Always wear eye protection, and follow proper safety precautions, when working with power tools.

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	Figure A
	Figure B
	Figure C

Remote Starter Wiring, Part 2

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.

• To connect the door-locks to the receiver module, begin by removing the kick-panel on the driver-side under the dash (figure A). Also remove the trim around the windshield to make way for the antenna wire.

• Consult the kit instructions to find the door-lock wiring configuration that fits your vehicle and follow the appropriate instructions and diagrams to begin the wiring process. In our case, the power door-locks are controlled by two wires beneath the dash console (figure B). One wire controls the "lock" command and one controls "unlock." (Many vehicles have single-wire controls for the door-lock systems.) These two wires must be connected to corresponding wires on the car-start module using a solder connection.

• In some cases, a relay (figure C) will need to be installed to tap into the power-locking system. In our case, however, there were relays already built in to the vehicle.
  
• Once the proper wires have been identified, strip a portion of the wire as described in the previous segment, and solder the wires for a secure, permanent connection (figures D and E).

  Important: Some vehicles require separate relays for locking and unlocking the doors. For door-lock connections that do require installation of relays, there must be a fused power supply to one or more leads in the relay.

  Figure D

  Figure E

  
  

  Figure F

• For best reception, we mounted the extended-range antenna on the windshield, just above the rear-view mirror (figure F). This position also keeps the antenna out of the driver's line of sight while driving. It's advisable to have an assistant standing outside the vehicle to tell you when the antenna is centered perfectly before attaching it to the windshield.

• The antenna lead-wire can be tucked in and concealed inside the headliner and run down behind the trim along the edge of the windshield. The plug end of the cable plugs into the receiver module.
  

  	Figure G
  	Figure H

• Two of the wires from the receiver unit must be run forward from the passenger compartment and into the engine compartment. One attaches to a pin-switch (figure G), a safety feature that ensures that, whenever the vehicle's hood is up, the engine is prevented from being started with the remote-control transmitter. In that way, when checking or working on the engine, the vehicle can't be started inadvertently using the remote.

• The switch can be mounted in a convenient location at the edge of the engine compartment so that the closed hood compresses the switch. When the hood is lifted, the switch-pin pops up and prevents the engine from starting. We fashioned a small metal bracket to simplify mounting the pin-switch (figure H).
  

  	Figure I
  	Figure J
  	Figure K

• To make the electrical connection for this switch, we fed the two lead wires from the passenger compartment into the engine compartment via an existing opening in the firewall (for the factor wire harness) through a rubber grommet (figure I). If your vehicle doesn't have an opening like this, you may need to drill a hole through the firewall. If you do, be certain to use a rubber grommet to protect the wires from fraying.

• With the engine-sensing and kill-switch wires fed forward into the engine compartment, follow the directions to connect the hood-switch wire and secure the connection with a crimp (figure J).

• With the wire connected properly, we then mounted the switch bracket on the side of the engine compartment (figure K) where the closed hood will open the switch and allow the remote starter to work.
  
• Because the engine's sensing wire was too short, we extended it and ran it around the engine. Whenever running electrical wire in close proximity to the engine, be sure to protect it using wire-loom (figure L).

• The second wire leading from the passenger compartment is routed and connected directly to the positive battery cable. This "smart-sense" wire signals the starter unit when the engine has been started so that the cranking mechanism will disengage. This important wire should be secured to the cable terminal by soldering (figure M). If this wire comes loose, it can cause the starter unit to malfunction and continuously "crank" the engine after starting.

  Figure L

  Figure M

  
  

Safety Alert: Never make a connection to the battery wires, or solder them, while they are connected to the battery. Always disconnect the battery cable first.

In the segment that follows, the final connections and adjustments are made to the remote starter, and the new system is given a test start.

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