Remote amp power not working

A little under a month ago I moved an amp/sub set-up from my Jeep to my 98 Monte Carlo.  Everything's been working great, except for lately the subs have been powering on randomly (they're not really powering off randomly, if they're on they're on til I turn the car off).  Sometimes it's right when the car fires up, othertimes I'll drive around a bit and they'll all of the sudden start kicking in.

At first I thought the inline fuse was blown on the remote, but I checked the amp terminals with a volt meter and it was registering, the problem I could see was that it wasn't getting 12V+.  It was coming very close, 11.8V at times or so, but still no turn-on from the amp (1400W Pyle, l know what usually follows saying that word).

What should I go after/check in this situation?  Could there be too much resistance in the fuse assembly on my remote lead?  Battery going downhill?  Any and all advise is VERY appreciated.

Check the ground point for the amp, and ALL related connections. Also, check the remote turn on lead.

Head unit? Stock? Hopw are you triggering the amp, if its a stock deck?

Head Unit = Pioneer DEH-45DH (1.5 DIN special model for GMs)

The remote turn on was delivering current to the amp, it just wasn't a full 12V when I checked it with my DMM (car was running).  Also the system has worked fine for a month, only showing problems turning on now (BTW the fault light has not come on any of the times I've been in the trunk while the car was running)

I haven't checked the ground resistance, but it was good enough a few weeks ago (Didn't DMM it but I was getting plenty of draw and not having any electrical problems).  I sanded the life out of all connection points on the ground, and it's a direct chassis connection.

For reference the remote turn on wire from my Pioneer goes directly into a .5A fuse before running the length of the car back to the amplifier.  I took some volt readings all with the car on:

Fuse case open, one terminal to the other = 11.8V max (bounces around closer to 11.7V)

Specific Questions:

Any other help is welcome as always :)