I am in the process of temporarily putting a front driver side door from a 1998 onto my 2000. The reason for this is an entirely different story.

However, I figure I should share my learning and frustrations in the event it helps someone later.

Toyota changed the wiring architecture pretty significantly after the 1998 model year when they introduced the "Multiplex Communication System". The biggest change I see is with how the body ECU communicates with various devices and modules including:

• DOOR LOCK CONTROL
• HORN
• MIRROR HEATER
• POWER WINDOW (REAR)
• REAR WINDOW DEFOGGER
• REAR WIPER AND WASHER
• THEFT DETERRENT
• WIRELESS DOOR LOCK CONTROL

When trying to connect the door you will first notice the two large junction connectors the come into the front kick panel from the door do not match. You also cannot re-pin them because the pin-type and layout is completely different for one of the two connectors.

You will also find that the connector for the window motor/regulator is a simple 2-pin on the 98 and 5 pins on the 2000. This comes from changes to the auto-up/down function based on the wiring diagrams.

Swapping the wiring harness is possible if you also change over the window motor. The other individual connections to the speakers, locks, etc. are the same. You may be able to splice in a 2000 wiring harness to the 1998 motor and still get up/down function. I haven't tried this yet but I will be attempting to transfer the harness and will provide an update on what I find.

Anyway, I would assume anything in that list above will not be plug & play between 96-98 and 99-02.