Brake controller question

I'm having a memory lapse with this question. I had problems last summer with not having the brakes on my trailer working, but lights are ok. I had both the trailer and vehicle in and it took a while but everything was working when I left. Next time I hooked up, two weeks later, no brakes. Did two trips that way. Took vehicle back, they said it was fine, needed trailer too. Never got back in but when I hooked up the trailer to put it in storage, I had brakes again. I would say a loose connection somewhere? My question is: I've noticed that I'm getting a readout on the controller now, as if the trailer was hooked up. I believe that usually without the trailer there is no readout on the controller. Which is correct? Am I nuts that without the trailer, there usually isn't a readout? If so, that would indicate to me that it's a problem on the vehicle connection (readout w/o trailer), not the trailer. I could get it checked now, if so.