In my car I have a car radio jvc Kw-av61bt with my iphone 6plus it work perfectly but now i bought he iPhone 7 Plus and it won't connect thru BT I DONE EVERY THING IM OUT OF OPTIONS NEED HELP

Thanks for the quick replay honestly this my first time posting for a ploblem . After checking all the step you have me I realize that I hand not do one thing and it was to go in the setting. Of the radio and delete if all pre existing connectio. To divorced that fox my problem I been troubling with this since novmeber 16