Alright, so I have a 2007.5 and also have an MM3.

After a while, the display wouldn't turn on and would blink lights, and after unplugging it and plugging it back, it would work.

Now it won't turn on and at all, and I noticed that my battery gauge is reading low too.

Knowing that these are power-hungry trucks, I figured that the batteries were the issue.

So then, after getting a battery test, I replaced both and made sure connections were tight. Well, it didn't fix it.

I am not sure what to do as im out of things to think of.

I also got an alternator test that also came back well.

Any help would be appreciated.