Help with Gentex Wiring

Did you find UL2 at the top of the driver's A pillar?

 

No, I have not, I am still debate with my wife to get the mirror or not, so I don't have chance to take look.

the connector is located at bottom of a-pillar, not top of a-pillar.

 

Ken or anyone,

I was testing my homelink mirror which came installed in our 08 Prius. It seems that car's homelink remote functions work without the switched 12v since it operates my garage door with the car off. The only obvious difference is the green light in the middle does not stay on constantly as it does with the ignition engaged. Perhaps the auto dimming is off also.

Does your homelink function work when the car is off (eg when there is no switched 12 from the power port fuse)?. If so, it would seem possible to get the homelink function without running extra wires down if all one needed was the remote functions.

 

We've had these mirrors in our other cars. I always wire them so that they are only powered when the ignition is on. That way, if the car is parked in the driveway, someone can't break the car window, press the button, and get access to our garage and home. FWIW...

 

Testing my "new" ebay Gentex homelink mirror I find that it draws zero milliamps on the constant +12 until a homelink button is pressed then it uses 50 ma (red led and rf transmission) for the button press duration.

If the EC "ON" button is engaged the mirror draws a constant 13 ma (probably the green led) until the mirror darkens when it draws around 180 ma until the mirror reverts back to normal.

 

Here is back-up light source (called LR1)and location. You can just tap in the "red" wire for reverse sign.

see attached picture for clarity.

 

How bad is this install for someone with reasonable technical skills? Has anyone done a write up with pics for the squeamish? This would be a first choice add for our hopefully soon to be v m3. W

 

The upgraded Homelink mirror with garage door remote functions is relatively easy if you don't want the autodim function. The homelink part only requires constant 12 v and gnd. Autodim is best wired with switched 12v which requires going down the side pillar.

But running the switched 12 vdc under the dash would be easy for someone who changed stereos, etc. so you could try it or pay a audio shop a max of $100 to do it for you.

 

For those who want to go to the fuse box, I found some tapped mini low profile fuses on ebay. These fuses have a wire lead coming out of one side of the fuse that can be hooked up to the mirror power wire. Looks like they might allow the fuse box top to stay on. I'll post more when I get them.. Finding the switched 12 volts is not easy in the maze of wires behind the driver side panel, so hopefully, this might be an easier solution for those who don't want to remove the a-pillar.

 

Are you saying you can get to the fuse box without going down the a-pillar? If so, how?

 

Yes. It was quite easy to do. I started by running the harness across the top of the windshield under the header lining and then crossed the harness over at the top of the a-pillar panel. From there, I ran the harness inside the panel by simply pulling back the door seal and shoving the wires into the recessed space under the panel using a nylon pry tool. I then pulled off the lower entry footstep molding to expose the end of the driver kick panel. I removed the kick panel by taking off the plastic head finger nut on the back and pulling the panel upwards. I connected the ground to the 10mm bolt on the door jamb and connected the 12V constant to one of the fat wires in the maze, using one of the supplied cable connectors. I could not find an ignition switched 12V, so I am patiently waiting for the fuse tap. I ordered two of them, so I might move the 12V battery lead to the fuse box once they arrive, just to give the whole job more of a factory look.

I couldn't see a simple way to remove the a-pillar panel and I was afraid to start prying around for fear of fracturing it.

The kick panel is easy to re-install IF you remove the two blue pop fasteners from the body, put them on the panel, put the panel on the firewall stud, line up the panel and press the two pop fasteners in. I tried for about an hour to replace it without removing the pop fasteners from the car body to no avail. Use a nylon pry bar to remove the them from the body.

Does this make any sense?

 

Whoops...I did run the harness down the a-pillar but I didn't remove it. Sorry if I misled you.

 

got it...

 

Monkey, Can you tell me where the UL2 junction box is? Is it at the base of the A-pillar? I see 2 junction boxes there.

 

Yes, there are two of them, just look at the pin location and double check with the colour of the wires.

 

When I installed my Gentex mirror which has compass, auto-dimming, and garage door opener, I followed the instructions provided which required me to run the wires across the headliner to the left A pillar, down the pillar to the rear of the instrument panel, down the back to the fuse box by the drivers shin and wire it there. My mirror did not have the outside temp sensor because the one already in the car was good enough for me. Thusly, I only had 3 wire to hook-up: Constant 12V, switched 12V and ground. I used a bolt next to the fuse block for the ground. Tied off all the wires as instructed, snapped the A-pillar cover back on and was done in about an hour. I chose this route because this is the one installed by the dealer if you buy that option and will not void any existing warranties on the car.

I have a Gentex at home I put on an earlier car and took it back off when I sold he car. This one has the full smash: compass, auto-dimming, outside temp, map lights, and a sens wire for the reverse switch to shut off dimming when you're backing up. Still works and I have the harness it came with but decided not to install in my Prius V because it would've been a bunch of overkill.

Anyone interested in buying it... I'll let it go.