Hi,

I'm replacing the OEM auto dimming mirror in my 2004 RX330 with a Gentex Genk40a Homelink mirror. The issue I'm running into is with the wiring. The original mirror is powered, but when I unplugged it, I noticed that all of the wires were black... This doesn't make it the easiest to determine which is ground, always on, switched power, etc.

Has anyone done this installation and can help me identify which wire is which in the wire harness? I'm trying to avoid having to run wiring from the fuse box to mirror if I can leverage the existing wiring. Thanks!

 

Welcome to Club Lexus elemenope!
Unfortunately, I don't know what wires are what in the harness. This is something that Toyota TIS (Technical Information System) might be of some help. You pay I think $15 and you get two day access to basically of the technical information that Toyota provides it's dealers with, including step by step how to's, wiring diagrams for lots of things, etc. TIS contains these things for basically every Toyota/Lexus/Scion ever mass produced. See link for more details.

https://techinfo.toyota.com/techInfo....toyota.com%2F

I am curious as to why you would want to replace the OEM mirror (unless it doesn't work anymore for some reason), as the second gen RX came with Homelink as standard equipment. But even if it quit working, what is the reason for going aftermarket?

 

get a multimeter or a test light and test each wire,

 

Thanks for the info Neelnaik! I'm the second owner of this RX and it just came with the auto dimming mirror without homelink. The wife really wants to ditch the garage door opener, thus the desire to change it out. I'll look into the TIS.

 

No problem!

I still don't understand your need for the aftermarket mirror, as the car has homelink from the factory. The buttons for it are not on the mirror itself, but on the overhead console (you will see three buttons labeled 1,2, and 3) just above the overhead lights.

 

I am with the others on this one. All you need can be found in the Owner's Manual on page 122, as seen here:

http://drivers.lexus.com/t3Portal/do...004rx33/14.pdf

 

I....am going to have to look for that. We've owned the car for years now and I never noticed those on the console. If it's there, I'm going to certainly deserve a /facepalm

 

Ok, so I'm feeling sheepish. Glad I came here first before being really mad later when I had installed that mirror... Thanks for the help guys!