I plugged int he rca's but he the lowest sounding bass possibe

if you have your front and centers set to 'small' you want your Bass out to be subwoofer only, and the rca jack labeled 'sub out' is the only place to connect your sub to if you want to control the frequencies with your reciever. I dont know the brand of your sub, or the inputs on the back of it to advise you where to connect, but it sounds like it worked for you at one time, but suddenly it does not

The jack on the guitars is a stereo type jack. The "ring" contact actually is connected to the battery and whenh the PLUG is inserted FULLY it coonects the ring contact of thee jack to the slkeeve contact of the jack which completes the circuit to turn on the battery. Hence while insertying the plug you will firsst get a snap as the tip of the plug ties to the ground of the guitar which is floating and picks up hum. Next the tip will touch the battery connection and get a snap. Finally when fully inserted both the battery is connected as well as the audio.
SOME guitars, especially those with tuners built inj will try tio fire up when the tip (audio) touches the battery cinnection. This may cycle and create the repetitive sound as it tries to start.

sounds like you have some wires crossed. check your radio setting and make sure that the subs are only playing bass and no trebble. buy some new rcas

Replace Audio output ic. Make sure you do not have sound turned off.

I Had the Same Problem I just unplugged my amplifier changed the fuse, also i had a fuse in the battery cable and changed that, unconnected the RCA wires and plugged them back in and then put new fuses in and plugged everything back into the amplifier and it worked again. If that doesnt work get back to me i will try to help you.

ont back of the set there are a set of jacks you can hook ext speakers to make sure that switch is turned to int speakers

Yea I had that problem one day as well.. all you got to do is go into the menu settings and check the box for the Int speakers... that should do it

Tune the gain on your amplifier powering the sub. Turn the Bass Gain on the amp all the way down and crank up your system to as loud as you can stand. Adjust the bass Gain until the Speaker begins to distort, then back off a little bit. This way you can crank it up and not get Bass Distortion early.

get a portable player with a head phone jack get one of those cables with a headphone plug on one end and RCA's on the other plug the portable player into the amp and hit play. If you get Boom then the RCA grounds in your head unit are blown and only a repair shop can fix that. Also double check all grounds making sure they are solit with the proper gauge wire. Under the rear seat belt bolts is a prime connection point. Check with different RCA's

The Amp stays on because you have a constant 12V to the Remote.
If your stereo remote is no longer working then run a wire from a 12 volt source that turns on and off with your ignition something like your radio fuse in the vehicle fuse box.
As far as the Bass Knob if it is connected properly and still not working check the line for wire kinks or cuts that may have happened during installation if you cant find any problems you can get a universal bass knob that plugs via your RCA cables for under 20 bucks.
Hope this gives u some ideas.