Well I am stumped with this.
I got a gentex out of a maxima with the auto dim, homelink, and compass. 3 wires thus should have been simple, as I had autodim wiring to start with.
Installed it and now the homelink works fine, but the autodim and compass work only in reverse. No D,N,P,3,2,1. Only reverse. The previous autodim came on properly and I am using the same wires.
You must have used the old disable in reverse wire, and put it into the pin that supplies power to the autodim/compass, so it's operating in the opposite order (no power till the car is put in reverse). I'm glad you mentioned it's from a Nissan, because I just snagged a Nissan mirror myself a few weeks back, so by freak luck, I may be able to help you out on this, as I found something rather interesting when trying to power it up. The HomeLink mirrors can get weird. Lots of variations and arrangements on the 10-pin harness. For example, I got the same mirror you're describing (auto-dim, HomeLink, compass) out of a Nissan Rogue. It's only 3 wires vs. the 4-wire auto-dim and HomeLink only one I grabbed from a Hyundai Sante Fe. It loses a feature, yet gains a wire. :th_scratchhead: This is why. Both have a separate positive wire each for the HomeLink and auto-dim (+ comp on the Rogue one), and both have a single negative. The reason the Rogue one doesn't have a 4th wire is because it doesn't seem to have a disable auto-dim in reverse feature, which is really odd, so it's possible yours may not either. This means you will have to run a new power wire for the auto dim/comp. OR, if you don't care about HomeLink not having a constant on power source, just tap both of them (HomeLink + auto-dim/comp) into the same preexisting power wire from your car. For now, if you're not too concerned about having HomeLink right away, you can swap the power wire over to the auto-dim/comp power supply pin. Here's the pinouts for mine:
The numbers start at the top right, and go up from there. So pin 5 (yellow and black) is the power supply for the HomeLink, pin 6 (red and black) is the power supply for auto-dim/comp, and pin 8 (solid black) is the negative. On my Hyundai mirror, pin 7 is the disable auto dim in reverse feature, so I presume if you stick the green wire off your car in there, it should activate that feature. Pretty sure the circuit board is the same for all of them in that regard.
Well I tore my mirror apart and checked it out. I didn't see anything out of the ordinary. I popped the screen off and all the pins and solders looked good so I'm not sure what's wrong with mine.
It's hard to say, as I've never really heard of a Gentex having an issue. Have you tried wiring it up to a power source and wiggling the harness to see if the power flickers on and off? I know the joints on a few of the Donnelly mirrors I opened up looked fine, but I resoldered them anyway, and it fixed the problem on all of them. But those definitely flickered when the harness was moved around, so I knew regardless of how it looked, they had to be bad joints.
