Auto-dimming rearview mirror & '06+ PT Domelight?

[Kell]

I recently picked up a Gentex 221 dimming mirror from ebay and wired it into my '06 PT.

I did run across one slight problem, however. Tapping into the positive wire on the dome light (to signal the mirror to turn on the led map lights when the doors are open/dome light is on) seems to have had a reverse effect from what I expected.

With the wire plugged into the mirror, the dome light comes on when the doors are open fine, but the mirror's map lights do not. Once the door is closed, the map lights turn on full time.

-edit-

It looks like the PT has +12v on both lines when the door is open, vs. the 0v when the door is open with other manufacturers.

Type B. Most full-size Ford and some Chrysler vehicles use a circuit that has two wires at the door jam switch. When the door is closed, there is +12 volts on one wire but not the other. When the door is open, there is +12 volts on both wires.

[Kell]

It looks like Gentex is supposed to have a switched circuit for the dome light line on the harness for Chrysler vehicles. However, it looks like this relay will serve as a stand in for it: DC60S3. They've been used successfully in other mfgs vehicles with a similar two-wire system, and this model doesn't chatter the way the smaller Radio Shack version does.

But, in the event anyone here wants to install an autodimming mirror in the future, here's my harness connections on a '06-09.

___PT............................................. ..Gentex
1) Pink..........................Ignition..........Bl ack/White....Connect to 12v lighter
2) Black........................GROUND.........Black. ...........Connect to 12v lighter
3) Black/Violet................Backup..........Black/Violet...Connect to backup lamps
4 N/A
5 N/A
6) Yellow/tan...................Dome light .....Black/Yellow....Dome Light/Door
7) C104 (11) Red/Yellow....Battery..........Black/Red........12v line (Always on)

The black/violet wire for the backup lamps is supposed to be at c105, pin 2 (located on the back of the instrument cluster), but the connectors for the instrument cluster have apparently changed into 4 separate connectors on the back of the cluster with the '06-09 update.


My thanks to Zapwizard for his '06 power windows guide - it made finding the c104 12v line easy.