Keyless entry installation is not a project for a beginner. These systems can be very complex and contain many features besides the keyless entry. Most systems include a car alarm, keyless ignition and more. Each car make and model has its own wiring system, so obtaining a diagram for your vehicle can make the process much easier. It will also be possible to program the remote for certain features. However, this should not be done until the end of the installation and wiring process. All connections should be made before plugging the main unit or harness into the system.
Identify Your Wiring System
There are several types of wiring that can be done for a keyless remote system. Determine what system your vehicle uses before proceeding.
Access the Wires
Remove the panels underneath the dash and steering column to gain access to the wires. It may also be necessary to remove the paneling underneath the driver's side kick panel. Locate the wiring harness and cut away some of the black wire covers to see the wires properly.
The color of the wires may vary depending on the car and keyless entry system. If a wiring diagram is not on hand, go online and look up the wiring diagram for your vehicle. This information can be found by performing a search on the make and model of the vehicle. If you have difficulty finding this diagram, contact the vehicle manufacturer.
If certain features are not being used such as a trunk, pop off of the auxiliary then cut these wires down to about six inches and tape them to the main harness with black electrical tape. This will keep them out of the way during the installation. Bundle together the wires that will be used and leave about four inches at the end of each in order to make the connections.
Make the Connections
Cut away a small amount of the covering on the wires in your vehicle's wiring harness. Normally a connection to the horn will require a relay. Strip the ends of the wires in the keyless system and connect them securely to the stripped area of the car wires. It is best to do the parking light, ignition wire, main power wire and starter wire connections before making connections to the vehicle's locking system. Side by side wire tap connectors can also be used to ensure a good connection. You should not have to cut any of the existing wires in the car harness.
Program the System
Once the system is installed and all the wiring connections are secure, you can program some of the remote functions. Some of the common programmable features include the door unlock pulse, ignition controlled door locks, chirp mode, ignition trigger feature and the passive starter defeat enable. Program the remote for your needs.
Easy Fixes for Keyless Entry Problems
Many keyless entry problems can be handled without a possibly expensive trip to the dealership. Most problems are very easy and quick to fix.
Replace a Dead Battery
If you press the button on the remote and nothing happens this usually means that the battery in the remote has died. You need a small screwdriver to remove the screw that holds the remote case together. Snap it apart and pull the battery out. Buy a replacement battery of the same type. Paying attention to the marked polarity on both the case and the battery, insert the battery and reverse the removal process.
Reprogram the Remote
You need to visit a website such as ProgramYourRemote, look up your year, make and model and follow the steps. In many cars, this includes looking in the trunk for a small two position connector, inserting the jumper into both contacts and pressing a button on your remote.
Fix a Fused Relay
One problem that is a little trickier to fix, but not difficult, is replacing the relay that sends power to the door locks. You can tell this is bad when you don't hear the "kachunk" sound you normally do when you press the button, but the panic feature works. The buttons inside the car won't work either. You need a standard 12-volt 30-amp relay, available at any parts store and a Phillips screwdriver. Find the remote, use the screwdriver to remove the screw and note well where each of the wires is located. Draw it or label it on a piece of paper. Pull the connectors off the spade lugs on the fused relay and relocate them onto the new relay one by one. Secure the relay into position and you're done.