after a small crash I get telemetry but no video (I get sensor error) is my wifi fried    I need HELP PLEASE

1st thing to check are the 3 white plugs that connect to the gimbal, make sure they are firmly fitted.
What exactly is the error you are getting ?
Do you get any errors when hooked up to the PT2 assistant ?
Other that that you will need to open her up and check all the connections.

I have checked the connections several times they are fine and the gimbal works perfect  but when I try connecting to the Ipad or phone it just keeps on trying to connect  so I try to take a picture and I get the error  everything else connects .  get picture of camera with ! (EXCLAMATION ) AND SAYS SENSOR ERROR I thought might be camera not connected  

I guess you have had a good look at the black ribbon cable ?
If it was the internal Wi-Fi unit then you would just get the blank screen, it does not give any error messages.
So it sounds like a internal problem with the gimbal / camera.

How small was this small crash ?

Sorry to hear about the small crash, it seems some modules were damaged when crashed, I do suggest you send it in for evaluation and get it fixed.

I have a Phantom 2 Vision, and a Phantom Vision 2+. I have not flown them for over a year, and then they only had accumulated a few hours fight time each at the most.
I gave the Vision to my son for Christmas so he could learn to fly and take pictures. When we started up the phantom Vision we had the same "no video feed" issues, and everything else was ok, but no video feed.
So I started up my Vision 2+: same exact problems!!! DJI has intentionally crippled the older quadcopters to force us to buy new models. This is outrageous!
Online, there are thousands of posts with the same exact issues.
I was ready to place an order for the new Phantom 4 plus, even after I bought the Phantom 4 last spring.
Now I swear I will never trust DJI again, unless they resolve the problems they created.