[KenWittlief]

the banner sensors do not detect light - they send out a red laser spot that is modulated in frequency, and it looks for that specific beam to be reflected back - usually from retroreflective tape - but they will bounce of a white surface a few inches away. with retro-reflective tape you can see the tape up to 20 feet away!

if you are getting output overload errors on the sensors you have one of the outputs shorted. The banner sensors have 4 wires - one for +12V, one for Gnd (or negative) one that acts like a closed switch when the sensor sees the beam, and one that acts like a closed switch when it doenst

you should connect the gnd and one of the 'sense' wires to the digital input of the RC - and dont connect anything else to the sense wires. Make sure the unused sense wire is not shorted to ground or power

if you had 3 fail on you, I suspect you are connecting one of the outputs to gnd or +12V - we smoked one last year (they are expensive too!)