dartalki

Yes, it would interfere with dead-reckoning if needed.

Not sure what wire the SPD signal comes in on. Wouldn't this defeat the dead-reckoning? Not that you would use it when you do need dead-reckoning, but just curious if it would. Are you doing this on a model that doesn't have the override at all? Like 2006+? I rewired my 1998 LS400 for navigation (came stock with Pioneer H/U). During this process, I learned a good bit about the way the NAV system works. The speed signal comes directly from the combination meter and is input to pin #12 (violet/white wire) of the biggest connector of the three (1. video & data\ 2. power & audio \3. GPS ANT). I haven't had any issues with the navigation system losing its place. I only use this feature when I need to change my destination or use other features otherwise unavailable during vehicle movement. I guess my system maintains its coordinate partly because I never lock less than 5 (min. 4) GPS satellites at ALL times. This was accomplished by relocating the GPS antenna to the back deck lid behind the the rear driver's side headrest to give the antenna a clear view of the sky. Once I've finish making my adjustments, I simply turn the switch back on and within seconds my NAV system re-coordinates itself if there are any discrepancies with the satellite signals, speed signal, and map database. On the 1998-2000 Lexus, I don't think we have the override sequence I hear about incorporated in our NAV units. This prompt me to use this method instead. I haven't had any negative experiences yet.

Has anyone tried momentarily interrupting the SPD signal to the navigation ECU ? I installed a push button switch that interrupts the SPD signal to the NAV ECU making it think the car is not moving. This allows me to makes changes to the navigation system only available when the car is not moving (ie. destination changes). The navigation system maintains its course/route and postion while the changes are being made because the GPS signal is still available. When done just reinstate the SPD signal.

Thanks dcfish !!! My email address is dartalkion1@aol.com :D

:o You will not be able to install the nav without a custom made wiring harness. There are no aftermarket solutions. Whoever told you that the car was prewired for nav from the factory owes you an explanation BIG TIME !!! <_< I may be able to get a wiring harness for you. If I may ask... How much have you paid for the system so far ? And exactly what parts have you purchased ? Can you get your money back ? Thanks for responding !!! I have spent around $750+ for the navigation screen, navigation ECM, GPS antenna, and navigation owner manuals... and unfortunately I don't think I can get my money back... I'm at a lost right as I don't know where to go next... If you have a custom wiring harness or know where I could purchase one I would appreciate it... I'm taking Electronics in college, so I have the ability to understand the wiring and componet part I just don't know what are my options, unfortunately if any... again, thanks for taking the time to reply !!! :( I'll look into it, Usually the harness is sold as part of the complete system. Thanks for your help and the "ADD"... I can be reached at dartalkion1@aol.com... Thanks again !!! ;)

:o You will not be able to install the nav without a custom made wiring harness. There are no aftermarket solutions. Whoever told you that the car was prewired for nav from the factory owes you an explanation BIG TIME !!! <_< I may be able to get a wiring harness for you. If I may ask... How much have you paid for the system so far ? And exactly what parts have you purchased ? Can you get your money back ? Thanks for responding !!! I have spent around $750+ for the navigation screen, navigation ECM, GPS antenna, and navigation owner manuals... and unfortunately I don't think I can get my money back... I'm at a lost right as I don't know where to go next... If you have a custom wiring harness or know where I could purchase one I would appreciate it... I'm taking Electronics in college, so I have the ability to understand the wiring and componet part I just don't know what are my options, unfortunately if any... again, thanks for taking the time to reply !!! :(

I recently purchased the navigation screen, ECM, and GPS antenna for my 1998 LS400. For what I understood the LS400 is pre-wired for the NAV system. Mine came stock with the standard setup (pioneer head unit, climate control, and CD changer). Is it possible to upgrade my LS to NAV, because if so I don't see the connectors I'm supposed to plug into the system. I've spent a good bit of money on these parts and now I'm fearing I can't use them. Any help would be greatly appreciated. Thanks !!! :(