This DIY is for people who'd like to install a keyless entry in a Rav that has not already been equipped with either a factory or aftermarket keyless entry or alarm. You can do this either for convenience, or as in this case, it is also a cheap, easy work-around for a picky driver's door lock.
If your power locks still work fine, but your driver's door lock cylinder is finicky or won't lock/unlock with the key, you can install a keyless entry instead of replacing the lock cylinder (and having to get a new key, etc).
Example:
My sister's '99 L (aka "Blackeye") came with factory power locks, but did not come with a factory keyless entry or alarm system; also, there was never an aftermarket unit installed. Therefore, locking and unlocking the doors has always been done with the key.
Due to some 18 years of daily wear, the driver's door lock cylinder has gotten very persnickety. It will sometimes unlock if the key is inserted a certain way, IF the key is a particular very sharp key, and IF you say "please". Thus, it is unreliable and so my sister has been using the passenger door to unlock the other doors.
Since this is impractical, I thought about swapping out the locks...but then I thought, "Wait, since the Rav doesn't have a keyless installed, it should be pretty straightforward to install one - right?" And guess what? I looked on Amazon last week and found this kit, for $12.99 shipped!
Docooler Car Remote Central Locking Keyless Entry System with Remote Controllers (the price has since moved up a little to $14.64 shipped)
I ordered it, and it came on Friday, so I got to work on it yesterday. This DIY documents what I did. It was very easy to install, and works perfectly! The remotes are sturdy and nice-looking, too.
Here is a picture from Amazon:

The kit I got was marked "K410". In the kit, you get the controller, two remotes (with batteries), and all the wires you need. The remotes are pre-programmed to the unit. You get installation instructions, but they are pretty confusing if you don't know what you're looking for. For reference, here are the installation instructions, with my notes (its one page, front and back):


Luckily, there is enough information on the internet to make the install smooth. The following steps show how I did this install on a '99 Rav4. Here are some important considerations before you start:
1.) This install will only work on a Toyota that hasn't had a factory installed alarm or an aftermarket alarm, especially if the alarm has a kill-switch or anything like that. If you're wiring doesn't look like the pictures you see below, then you might have some kind of system installed and not know it. You can call Toyota with your VIN and they will tell you over the phone whether or not the car had a factory install. However, they wouldn't be able to tell if there was any aftermarket work. So be certain that you don't have a system before you try this.
2.) Toyotas use the "type-B negative" trigger. You can view that in the circled configuration above.
3.) These kits generally come with other features, such as flashing the parking lights when you unlock the doors. I only am using the lock/unlock feature, so that is all you will be see here. Adding the parking lights just requires you to track down the wires and tap them like you see here.
4.) Use all the standard safety precautions while working with wiring. Keep track of your metal tools. You'll notice that I disconnect the battery alot! Better safe than sorry.
5.) The harness and wire colors may vary by country or some other reason, so verify this with your own research and multimeter.
2.) Toyotas use the "type-B negative" trigger. You can view that in the circled configuration above.
3.) These kits generally come with other features, such as flashing the parking lights when you unlock the doors. I only am using the lock/unlock feature, so that is all you will be see here. Adding the parking lights just requires you to track down the wires and tap them like you see here.
4.) Use all the standard safety precautions while working with wiring. Keep track of your metal tools. You'll notice that I disconnect the battery alot! Better safe than sorry.
5.) The harness and wire colors may vary by country or some other reason, so verify this with your own research and multimeter.
TOOLS:
Phillips screwdriver
10mm socket or wrench
Electrical Tape
Wire stripper/crimper (or you can improvise)
Small zip-ties
One medium u-shaped connecter/terminal (not absolutely necessary, but worth tracking down, something like this)
STEPS:
1.) Remove the kick panel door trim. You can pull it up with you fingers on the inside part, and it will unclip from the three red clips shown below. Also remove the foot panel (not shown), which just pull out once the kick panel is removed (sometimes there is a little black cap that you have to pull out). Remove the panel under the steering wheel as shown below, then then the metal part behind it.


2.) Inspect the wiring. Look at the pictures below -- one shows my sister's '99 that has no system installed, and the other shows my '00 that has a factory system. Make sure you don't have an alarm system!


3.) Disconnect the Blue 16-pin harness shown. After this is disconnected, your power locks should stop working. If they still work with this disconnected, then this part of the DIY will not work for you. (You will have to search out where your lock/unlock wires are, and then use that instead.)


4.) Look at the Blue harness, and you will find two thin wires, next to each other, that are Blue/White and Blue/Yellow. Look at the picture below. These are the wires that you will tie into for locking and unlocking the doors. Please note that there is a second, thicker Blue/White wire in this same harness -- don't use that one. Use the Blue/White that's next to the Blue/Yellow.

5.) Label the controller wires. You will have a bunch of wires that you're not using if you are just installing the lock/unlock function. The wires will be connected as follows:
White on Controller --> Blue White on Harness (lock)
White/Black on Controller --> Blue/Yellow on Harness (unlock)
Red on Controller --> a constant 12v source in the car, or to the battery
Yellow, Yellow/Black, and Black -- > all tied to ground
Not used: Orange, Orange/Black, Browns, Green.
White/Black on Controller --> Blue/Yellow on Harness (unlock)
Red on Controller --> a constant 12v source in the car, or to the battery
Yellow, Yellow/Black, and Black -- > all tied to ground
Not used: Orange, Orange/Black, Browns, Green.

6.) Disconnect the battery on the Rav.
7.) Locate the ground. You should see a nice bolt directly into the body, like this:

8.) Splice the Controller's Yellow, Yellow/Black, and Black wires together. These will all be grounded. Use a u-shaped connector/terminal block/cable lug to get a good ground (crimp it well). Slide the u-shaped connector under the ground bolt and tighten the bolt well.


9.) Splice the lock and unlock wires to the harness's lock and unlock wires. Review the suggested splicing method below to tie these wires. Do not cut the harness wires -- just strip the wire about an inch, and follow the method shown below, or if you have a better way, do that.
Splice the Controller's White wire to the Harness's Blue/White, and the Controller's White/Black to the Harness's Blue/Yellow.



10.) Connect to the a 12V constant power supply. In the Rav, there are several spots to do this. I picked the 12v constant by the fuse box. It is the thick, White wire in the picture below. I tied into it using the T-splice shown above.

11.) Plug in the Blue 16-pin harness (it will click when properly seated). Connect the battery. Test the system -- you should be in business! If not, double-check your ground connection, and that your harness is connected properly. If not that, double check your splices.
12.) Double-check all your connections. Select a spot to mount the Controller. I found that I could wrap a zip-tie around the Controller like a belt, then zip-tie it to the metal bracket shown below.

13.) Wrap up your loose wires and clean up the space. Take a final look and it will be something like this:

Now you can replace your panels and enjoy the keyless entry!
Final notes: I noticed with one of the remotes that the button part got stuck under the plastic when I pressed it the first few times, and so them the remote wouldn't work -- the blue led on it wouldn't lite up and it wasn't sending a signal to the Controller. I popped the remote open using a dime, and just repositioned the rubber button part, and it work fine after that. Overall, I am VERY pleased with the price and quality of the system, and I really like the remotes. I would buy this system again.
Please add any comments that would be useful, especially if you see something here that doesn't look right! Thanks