Iceman, the unit may be dodgy but before you write it off as that.........back to very very basic basics....................................
Recheck all the wiring thoroughly, both that you've got the correct wires on the car and the correct wires (and not being funny ,you understand the diagram) for the unit.
What should happen is theres one wire goes to the brake light. That activates the front sensors when you brake and it lights up so they are "dead" up until that point. Theres a second wire which goes to your reverse light which does the same when that is lights up and up until that point theyre dead or off. Theres a third wire which must be earthed.
Connect the buzzer.
Then connect
all of the sensors. They are usually numbered. Although they will each fit (on the units I've seen) any of the sockets on the unit, you must follow the number coding or order of them. If you dont you may find that your problem stems from the fact you've got a mixture of front and back on each circuit.
Have you fitted as per the instructions and numbers on the sensor wires? ie 1 to 4 on the back with 5& 6 to the front? wont make any difference technically but if youve got 6 on the back and plug it into a front measuring socket :doh
It literally doesn't know whether its coming or going
:thumb2
If this doesnt work send it back, it shouldnt beep when you brake if theres nothing in range (or theyre disconnected)
Things like this are usually down to daft arse mistakes, we all do them, youre taking advice here from the person who got the hot and cold the wrong way round on the washer so the cold washed delicates.............:augie
Or I wired the relay for a set of spots to the side light wire.......................:augie