Reversing sensors

[andyduds]

I have a Ford Focus with reversing sensors on which don't work. Recently I have just had a new reverse light switch fitted. The sensors still don't work. I've disconnected them one by one and still not working. When I first start the car and put it in reverse I get a long beep. Any ideas? 

Thanks

[Tdci-Peter]

12 hours ago, andyduds said:

I have a Ford Focus with reversing sensors on which don't work.

Check that the reversing light works. This uses the same switch. Then have a look inside the driver side boot cubby hole (pull out the lining, or better, remove the side trim panel). The module should be in there, check its plugs. There is also a connector mounted under the car, under the back bumper, not far from where the sensor cables pass through a grommet.

I think each of the sensors also has a connector, bit difficult to get at without removing the rear bumper. However removing that bumper is pretty easy.

If all connectors are ok, it is probably the module, or one of the sensors at fault. The Ford sensors are a ridiculuos price, and the module even more so. Mine failed a few years ago, I just replaced the whole assembly with a cheap unit off eBay, that was under £20 the lot.

The main module fitted nicely in the same place as the old one. It can be powered directly from the reverse light, needs a wire across the car (I have only one reverse light), except I had to go through a relay to disable it for towing. The sounder was just put under the lining of the cubby hole, and adjusted in position for suitable volume (bit loud if un-obscured!).

The sensors fitted in the existing bumper holes using the surround parts off the Ford sensors. It has worked pretty well, much better than continuous beeping!

I did not bother with the display, too much hassle.

Kit looked very much like this: http://www.ebay.co.uk/itm/Rear-Car-Reverse-Parking-4-Sensors-Reversing-Buzzer-Alarm-Kit-With-LED-Display-/172243272307?hash=item281a7fc273:g:MXgAAOSwbYZXYml7