Readeon and I had been going back and forth via PM on this. So others know how to do this, here is what he did:
On the combination meter (its the main gauge cluster (speedo, odometer, etc... its actually the ECU that controls the MFD and a few other systems)) there is a single 40 pin plug. You have to ground pin 18, that disables the MFD from going into reverse video mode.
ALSO, if you are installing a OEM navigation headunit like Readeon did, you have to send a few wires from the MFD to the headunit
The REV (pin 2), V- (pin 15), CGND (pin 4), CA+ (pin 12), V+ (pin 14) need to be taken off the E11 socket for the MFD and sent to the navigation headunit. On non-nav equiped HL's they go to the MFD, on nav equiped ones, they are not there.
Here is the E11 socket for the MFD
As for where the video/rev wire go on the back of the navigation headunit...
The REV wire goes to socket E5 pin 5.
The 4 video wires all go to socket E4:
V+ (pin 22)
CA+ (pin 24)
CGND (pin 21)
V- (pin 23)