I'm sure this has been covered but I couldn't find anything by searching. My Range was slightly rearended and the park sensors were still working fine. I got a new bumper and installed the parking sensors and now they are not working. I just get a long beep followed with the patk sensor light flashing. I checked the connectors and all are solid. I have heard if you put your ear to them they should make a noise? How can I determine which sensor isn't working? Thanks.