HERE'S ANOTHER THING TO CHECK!
I thought I had fixed mine using the soldering technique...but alas I did not fix it. My connections were good, but that wasn't the problem. The problem ended up being one of the resistors (I think) on the board. It's soldered connection on one end had cracked, and was only making momentary contact with the board. I discovered this while having just the board connected to the harness (no black housing attached), and my finger touched the diode and the clock fired up! Took me a while to see the crack, but there it was!
The resistor (I think that's what it is...not sure), is a rectangular component on the BACK of the board (opposite the clock face). You'll see at least 3 of them, and they are labeled with a "270", and that's all. The one that was cracked on mine was the bottom one, running horizontally. The other two are vertically oriented. I just re-soldered that guy, and it works great!
Good luck!
EDIT: It's probably a resistor, not a diode. See this write-up for a Subaru for a similar problem:
http://jasonrowe.com/2007/02/17/suba...tal-clock-fix/
The component looks the same, but on our clocks it's on the back side of the board, and says 270, not 510. Same little crack, though!
EDIT 2: Here's another Subaru example:
http://www.subaruforester.org/vbulle...snt-work-3350/