2007 Tahoe LTZ Navigation system help...Please...


New Member
Sep 30, 2016
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Help Please!
Here to pick your collective brain on a Nav issue...Im stumped..
After a lot of lurking, reading and searching Im giving up and here to beg for help on a navigation unit. Here is the background:
2007 Tahoe LTZ, no factory navigation unit.
I decided to buy one and after locating the correct part number.....thanks GM....I found a dealer on Ebay who had 5 new ones in stock, still in the factory packaging. I bought one and followed some install instructions I found on youtube. Seemed very straight forward. I got the unit installed, the antenna installed and powered it on. After asking for a code I inserted the dvd map as instructed. The unit popped on and looked awesome.
Every function worked and I went ahead and got the XM radio running too.
The Navigation screen works just fine, shows the vehicle moving and looks accurate. Here is my issue. When I program a destination, the unit accepts it maps it out and then speaks saying follow to the highlighted route and navigation will begin. The route is also a different color, like a red looking color. The unit tracks the vehicle just fine but there is NO turn by turn. The only other time the unit speaks is when you arrive....saying you have arrived at your destination. Not a sound during the route.
I went thru the menu, made sure voice prompt was turned on...volume was up ect. Still nothing.
I have read about a VSS wire that might cause this if not connected. Mine is connected at the box in the floor top left of the drivers floorboard. I located the wire based on instruction in the youtube video which guided to a green wire with a white stripe. I did NOT cut and splice but I did use a t tap connector.
Any idea of help on this? Everything seems plugged in ok, looks good on screen.....the woman just wont give me turn by turn direction lol.
Looking at a simple google search there seems to be a lot of this issue but the VSS wire always seems to be the problem. ....and I believe mine is connected to the right wire.
Folks.....I greatly appreciate the expertise of anyone that can jump in and help me out here.
Thanks in advance