hey all, well i did the vss wire mod that was in the "strange gps navigation problem" post. i had the same problem everyone else has in there 2001's without onstar. it would move the little red arrow but once every 4 blocks or so. the mod was pretty straight forward and thanks to the pictures posted it took me about a hour and a half to so. the hardest part i say was crawing under the kick panel and digging around in there trying to solder. i accdentially cut the vss wire in half and had to take another piece of wire and use it as a bridge. soldered it all up and its working. the little arrow now moves along with the car whever it goes. if you do this make sure you solder the wire as far back on the harness as you can. otherwise when you put the nav unit in it will push the vss wire right off the pin and you will have to re solder.
also, no need to go and buy the GM GPS Antenna Listed for about 50$ shipped through sites like gm parts source or whatever. you can go on ebay and get a generic gps antenna with a SMB Female connector end and you will be set. i paid about 20$ shipped. all and all im pretty satisfied and excited. thanks to everyones help here for the pics and directions on how to wire everything up.
2001 Aurora 4.0 122k Mile-Catless, K&N Filter, 8K Hid Kit, LED Reverse Lights, License Plate Lights, and more.
Hey mlear, all of those guys are long gone. But it looks like you're really set on making one of those decrepit nav units work, so I did a little digging for you...
The VSS signal wire comes in at the driver's side footwell and ultimately goes to the instrument cluster, it should be DK GRN w/WHT STRIPE. I'd start looking for a place to tap as close to the cluster as I could get, but you may have to remove the kick panel and dig it out of a bigger bundle. Just use a t-tap unless you have superb soldering skills in very tight spaces, lol!
On the headunit end... And I can't verify this without a '02 or '03 FSM, but a couple of posts indicate that the VSS wire needs to go to Pin B8 on the nav headunit.