Can someone please tell me which of the red, yellow, blue, green and brown wires on the dimming mirror are constant-12 volt, ignition-12 volt and ground? I'm installing a new Gentex mirror with only those three wires. Thanks!!!!

 

It looks like red is constant. Brown is ignition. How do I fund ground? My guess is it's blue

 

Multimeters... They are handy for these situations.

 

I have a Multi meter. I did use it to figure out the constant and ignition 12 V wires. I was unsure about ground and what the other two wires were for. I used the Continuity setting to determine the ground wire. I held one wire on the cars body and touched each of the five wires and got continuity only on the blue. So, I no longer need the help, but maybe this post will save someone else a few minutes if they decide to swap mirrors.

 

I will try to wire up a radar detector soon so this will come in handy, I would use the blue and brown I guess

 

That may have been good enough yet it still could be a power wire that circuits to ground.

Take one lead (+) of your multimeter and connect it to your known 12 volt wire - I would use the brown wire that's hot with ignition on. Then check the blue wire again with the other lead (-): with ignition on, off, on with lights on etc. Make sure it remains a ground with the car on and lights on etc. You could also check your continuity like you did before yet do it with car on and again with lights on.

I don't claim to know what wires are what on the Lexus RV mirror yet have done several mods powered off rear view mirrors with strange and or different results on wiring - especially when looking for a true ground.

Just my experience talking etc..

Cheers

 

The red and brown wires were the only ones that showed 12 V at any time.

 

To access the wires easily, just pull the panel directly behind the mirror, straight down. The Molex style plug is white and you only see it if you put your head close to the center console display and look back underneath the sunglass holder

 

Hope this helps!

 

I had that diagram. Couldn't make heads nor tails of it, LOL