i just installed my avic d3 i only getting one sat bardid i do sometinh wrong

Park the vehicle outside and leave it for about 10 minutes with the unit on. Then check it again. If you don't have more sats then something is wrong with the antenna location, the antenna itself or possible the unit (unlikely).

I installed mine in my garage and when I was done I had a very weak signal too.

Other people here could give you better advise if that doesn't work.

Where did you put it?