I screwed up! I hooked up a Bluetooth integration device into my '03 ls430 UL and it totally knocked out my NAV (to black screen) and also the only control I have over my head unit is on / off. I cannot control the volume, I cannot play the AM FM, nothing. I can still control the cd changer but that's it. I totally unhooked the device and the head unit and GPS stayed the same. The NAV monitor does show the "cd info" and also shows when I turn the head unit on/off so it seems the monitor itself is functioning normally.
Has anyone experienced anything like this before?
I'm thinking that I need to totally reset the GPS and head unit.
Any other suggestions or insight?
Thanks

 

Pulling the negative in the battery for 10 seconds resets the navigation. Sounds more serious then that. You may have shorted something out.

 

Check the radio fuse, located at the foot well passenger side, should be 7.5a

 

After opening up the NAV unit (in the trunk) and resetting it (found instructions on this via Internet) I realized that the actual problem was that I had loosened the wires that plug into the screen from the head-unit/tape-player.
So.....for future reference, if ur NAV screen is black but it still flashes the functions of head unit (ie "power on/power off" or shows the info on the cd that's playing), check the connection that runs between the head unit and back of the NAV screen.
Thanks everyone for ur help and suggestions!

 

While hooking up the vaistech unit it did the same thing (made the nav screen go black). This time I knew the vaistech was actually made for my year car (the grom unit was actually made for the 04+ and wasn't supposed to be compatible with 01-03's made in the US) so I started investigating and found that all I had to do was press the "map" button on the nav and the screen started working normally.
So basically for some reason when hooking up these kind of units, it makes the screen go black as if I had turned off the screen (in the setting options of the nav) and all u have to do is hit the "map" button to get it back on.
That simple... and boy do I feel like a dummy!
Oh well, u live and u learn.
Hopefully someone else can learn from my mistake!
Good luck