You are right that the parts diagram will not show the connector separately.
However, most Toyota connectors are readily available for repair purposes. They usually come in two parts: the connector housing, and the wire pins w/wires to insert into the housing. The challenge is to find the part numbers for the connector housing and the repair pins with wires. Perhaps your dealer's parts department can help you find the part numbers.
Another approach would be to get a used head light assembly from Ebay or a junk yard.
There are two ways to go about finding the part numbers for the connector housing and the repair wires w/pins, but both require access to the TIS (Toyota Information system). You can get a subscription to TIS, or see if your dealer will access it for you.
1. Every Toyota connector I have seen has the part number molded into the housing somewhere. It will be very, very small. With that part number, you can look up the housing on the "Wiring Harness Repair Manual" for your vehicle in TIS. The wiring harness repair manual will also show what repair wires are needed for that housing, and how to insert them into the housing. Special tools may be required to insert or remove a wire pin from the housing.
2. TIS will have the wiring diagram for your vehicle. With the wiring diagram, it will show the details on every wiring connection in the vehicle. Those details will include a "connector reference", wire colors, pin numbers, etc. The connector reference number is cross referenced in the wiring harness repair manual to the connector housing part number.
I have access to the wring harness repair manual for the RAV4, but not the 4Runner, so I can't help you there.
Good luck..
