Are you usin the scan do 800? If so hit the test button and look at the color bars and compare it to your laptop. It could be the blue and green are reversed.
I just tried it - When I hit the test button once - I get nothing, just a blue screen. When I hit it a second time, I get a green screen w/ a black bar on the left.
edit: just checked that manual you linked:
4.2 Using the Front-Panel Controls
TEST BUTTON: This button will force your Converter to generate one of two
test signals on its COMPOSITE and S-VIDEO outputs. (These test signals are
not available on the RGBS output.) When you press this button once, the
indicator LED on the button will light up and the Converter will output a
“color bar” signal. When you press this button a second time, its LED will stay
lit, but the Converter will now output a “grayscale ramp.” When you press this
button a third time, the LED will go off and the Converter will resume
outputting images received from your computer.
I see. Can you power the scan do inside and use the rca composite connection to a television and see if the color bars look ok on the tv. Split the problem to see if it is the scan do, wiring to Nav Screen or something else?
If I use the composite it works OK, sort of blurry, but colors are correct. So it's not the Scan Do. Must be the cable I made between the Scan Do RGBs out to the screen wires in my trunk for the LCD. I'll play with it tonight and see if I've just got something backwards. Thanks for your help.
So in the trunk there's a serial cable spliced into the RGBs out from the back of the nav unit. There's only 4 wires (RBGs obv.) I verified they're correct via an Acura wiring diagram. My question is - where should the ground out of the Scan Do go (pin 1)?
I'm not sure for yours, but in my car (mazda) I had a ground. Try checking the wires with a DVM and see if one of the wires reads 0 ohm to the chasis and try that.
And for the bare wire that's inside the serial cable? I don't really know where to terminate that inside the metal hood I have...