Ir Rangefinder issues

I hooked up the second robot and programmed it with the same code as the other one but it kept crashing and resetting. After about and hour of debugging we narrowed it down to the Ir rangefinders. Unfortunately, it's not the sensor itself but something wrong with circuit.It only crashes when both of them are plugged in. I'm guessing there is a short from one of the grounds to a dataline on the opposite side. Either way, that means we're going to have to pull it all apart again to try and find the short. Not fun...