Installing Amp And Sub int Stock Head Unit

I am having some trouble installing a amp and sub into a stock radio. I amp works and the sub works. The amp will turn on but will get nothing from the sub. I got the Level Output Converter hooked up but I am not sure if its correct . Any suggestions or anyone know the right way to do so

thanks

I had a problem very similar to that I had to take the 2 rca plugs where it goes into the conv. and get another plug that has 1 male end with two female ends plug those together and just forget about the other plug on the conv. if that makes any sence

take it 2 best buy they installed my amp and sub with no problem

the problem with this is you lose two of your speekers. first make sure you are hooking up to the correct ones. you want to cut the rear sweeker wires. touch the +/- to each side of a battery the speeker will pop telling you with speeker that wire powers. if you have one fr and one rr it wont work. if this is hooked up right and does not work there should be an extra wire, brown or black, hook this wire to your stereo grownd. make sure all your speekers work before you hook it up. good luck