craftsman door opener wont accept remotes/keypad
i have 2 craftsman openers, one side works with the keypad, wall switch, and 2 remotes. the other unit works only with the wall switch. i tried programming remotes per the manual, but it will not accept them. i swapped this unit with another unit that i verified was working with remotes, and now it will not accpet them. the learn button is flashing, but all sensors are functioning properly, and the door opens and closes fine with the wall switch. since 2 different units have been mounted and both will not accept remotes, even though one did while installed elsewhere, does the problem exit within the wiring in the garage?