I'm new to this forum, just installed the x850bt. Everything works great except the GPS. The map itself is stuck on the location I was when I installed the unit. The arrow and map won't move when I drive. I drove a few miles away then input where I was when I installed the unit to guide me and it just tells me I'm already there.any input would be appreciated. Thanks

Where did you mount the GPS antenna?

Right above the radio underneathe the dash. It says that the GPS signal is good.

I literally just installed my 850bt yesterday, have the GPS antenna under the dash as well. It's probably not as strong as a connection as it would be outside, but it still picks up 5+ satellites. Takes a few minutes longer the first time you hook it up, I think.

Did you mount it on the little metal sticker plate they sent? I have read that helps.

It's mounted on the sticker that it came with, I think it was picking up 3 satellites.

The more I use it, the better it seems to get. I reset my GPS settings and now it seems not as accurate, but its still moving. I am having issues with my XM antenna under the dash, I am reading that you are going to want to move them as far up towards the windshield as you can