Reverse sensors not working

[Langers1710]

I have 57 plate Audi Audi A4, it came with parking sensors and a rowbar when I bought it 2 years ago, finally got round to removing towbar as didn’t need it and looked bad, but since then my reverse sensors haven’t worked. Looking at the sensor module, it’s got the name gadget man on there and 3 wires coming out (red, yellow and green) that have been cut. I’m guessing one of them is the feed and the other 2 come from the light connection?? Anyone else had any issues? Stupid idea just cutting them all off and regretting it now. Can’t seem to find the manual for the sensors but really want them working again.
Any help would be great

 

[NHN]

As it's aftermarket, it may have a link into the towbar so when you're towing the sensors are disabled, I would plug the towbar back in & see if it comes back to life.

OEM towbar & sensors are coded to eachother so to speak so if towing the sensors get disabled automatically also.

Without spending time on checking the sensor unit, I couldn't say right now what's going on, but try above.

 

[Langers1710]

Unfortunately the wires were cut from the towbar unit, that is the one in 2nd picture. Not sure what to do as threw away towbar that I removed as it was in real bad condition and was never going to use it. I trained tracing the cables back from aftermarket sensor module but no idea where they go