FITTING AN OEM WIDESCREEN SATELLITE NAVIGATION SYSTEM
IN A NON-NAV LEXUS GS

Project
Parts
Photos
Pinouts
Plugs

This set of pages document a project to install a widescreen, touchscreen satellite navigation system in my 2002 Lexus GS300. Buy the bits and pieces required and you too could add this nice feature to your car!

Firstly, thanks must go to Anh Dang (BananaGS) who showed that such a project can be done!  One of his projects involved putting a non-widescreen navigation system in a 1999 GS400, which uses different wiring and different parts, but gave a useful insight into the way the various parts communicate with each other.  If you use either my or his projects as a guide, PayPal him a few quid for a beer, the link's on his site.

The navigation system consists of a touchscreen display in the centre console, replacing the radio and air conditioning controls, a navigation computer in the boot and a GPS antenna (which I mounted beneath the eye-level brake light where it can't be seen and isn't shielded by metalwork).  The cables linking the navigation computer to the screen and the speaker go in the cable run down the right-hand side of the car, underneath the doors, then up and around the back of the combination meter (the "clocks").

No major dismantling is necessary, the only things I needed to remove were:-
 All of these are easily removed.  The combination meter surround, ashtray and clock/vent assembly all pull out when you can get a grip on them.  Plastic covers either unclip or unscrew.  The glovebox unscrews AND unbolts (but watch for the yellow cables on a mounting plate in the roof of it).  The boot lining unclips (when you can prise the push-in clips out) and unbolts.  The radio unbolts.  The combination meter unscrews, as do the door sills.  The brake light just pushes about an inch to one side then lifts out.

Tools required:-
 The Lexus Techdoc site is an absolute godsend, and is cheap too! €3 gets you an hour online, plenty of time to download any wiring diagrams you need in PDF format.  If printable versions are available grab them, as the normal diagrams can be VERY wide and you have to print "current view" whilst looking at different sections of the page to get a useful diagram on paper.

The relevant sections in the Electrical Wiring Diagram section are:-
 Download ALL connector lists to make sure you've got the ones for your particular car.  If you're scrounging plugs from a different model in the Lexus or Toyota range, go grab as many of these connector lists as you can to improve your chances of finding what you need.

The System Circuits pages contain colour diagrams of connections, but may only cover older systems (such as the non-widescreen navigation system).  Grab them anyway, they may be useful.

The Overall Electrical Wiring Diagram is a goldmine, though, and should cover everything you need.  You'll want to grab every diagram you can find, regardless of model version and age, as some cars (such as mine) seem to have features of one diagram mixed with features of another, such as Mark Levinson radio wiring coupled to a non-Mark Levinson amplifier.

In both the System Circuits and Overall Electrical Wiring Diagram sections you'll want to download all pages covering the following:-
 Links between diagrams are easy to follow, they give a page number (which is in the top-left corner of every diagram) and a column number (so you know where on the page to start looking).  In some cases two page numbers are given, often this is to cover LHD and RHD variants.

While you're on the Techdoc site, see if you can get to the Repair Manual, and from there go to Lexus Navigation System.  The system has a built-in service menu, and the "Pre-Check" page tells you all about it.  Also there are a load of troubleshooting pages, handy if your nice new nav system isn't doing what it's supposed to.

The rest of the pages on this site cover the parts you need, connectors you'll encounter, a list of what connects where and photos taken as the project progressed. Enjoy!