As a veteran installer of 15+ years, I have never had a problem with a Metra harness that wasnt a result of user error, and I have personally installed thousands of head units. Not saying they are flawless, but they have one hell of a track record in my eyes.

Your issue sounds very much like a loose connection. I would start by taking the deck out but leaving everything connected & with the key on and the system playing start wiggling around the wires and plugs to see if you can replicate any of the symptoms (& observing what you did to cause the symptom).

Also look for any cuts or kinks in the wiring that could be causing a short circuit to ground, there is a lot of very sharp exposed steel inside the dash.

If everything passes those tests I would question the condition of the deck itself. A cracked solder joint somewhere inside the HU could cause this, and if the device has one cold joint it likely has many. With the deck in your hand & playing give the side & bottom a firm & solid smack with your palm, see if that does anything.

 

The bass staying on is because they run through RCA and obviously those connections are good. As stated just pull the deck out with the power on and music playing and have a wiggle. The culprit will soon reveal itself. You may have squished the wires when you put the deck back in. I know in mine I had to really squeeze the harness and all the RCA and Video out cables to have them fit comfortably.
Have you had the deck out at all since install? It's a 5 minute job to pull it out and do some testing.

Berz out.

 

Yeah, what you guys mentioned was my plan of attack. I'm tired of hearing it cut out and wanted to see what light anyone here could shed. I'll let you guys know how I make out.

 

Wasn't able to replicate the sound cutting out to just bass, but I gave the deck a good bop and it powered off and rebooted. Heading to Crutchfield now to make a purchase.

 

I have the Kenwood DDX771 and it's an awesome deck so far. See what they have in stock. They should be getting cheap now.

Berz out.

 

Got a pioneer, 100$. Single din BT and CD with remote. Actually bought two, one for another car I have as well.

 

Well, made it almost a month. On the way home from work, the sound cut out to just bass multiple times. Other than that, the unit has been sounding great. What the hell is going on?

 

Found a couple threads with my same problem. I wasn't really being clear enough before. When it cuts to just bass, I meant just the sub is working. Speakers are dead.
Found possible contact marks on inner door shell. Laid down some duct tape and will wait to see if problem arises.
I was leaning towards the amp being bad til I saw that thread.