Can someone tell me if this sounds like it might be correct... I recently installed a Z-1 in my 07 Silverado (new body style). I took a 30 mile drive and the navigation worked great. Later that same day I got in the truck and the navigation was no longer working. Everything else on the system (radio, dvd, tv tuner, xm tuner, bluetooth) still works great. But the unit says location not available due to hardware. Took it to several installers and they all said that the wiring is correct, and that it must be a faulty unit. So the dealer I bought it from is going to replace it for me. However, the last installer that looked at it said that the 07 vehicle that I have is known to have a very low amp supply thru the factory radio harness. Considering the fact that the unit worked fine at first, he thinks that maybe I caused a power surge from having all of my components (Avic Z-1, OS3-Bose, SWI-PS, TV Tuner, XM Tuner, Back-up camera) wired into the factory radio 12v supply and accessory power wires, which damaged something in the Z-1. He drew up a wiring diagram for me which involves wiing all of the 12v wires to the main power wire at the fuse box, and using a resistor. Any thoughts on this? I don't want to go thru al thi work if it's not right. But I also don't want to install my new unit and have he same thing happen again.

if everything is working fine besides the navi it sounds like the unit itself might be having a problem running the software. Also I would check the antenna signal and make sure it has a good strengh signal going.