you go about it something like this:

step 1: fused distribution block


step 2: I am going to guess you will need to upgrade your fuse that is under the hood also. (to a larger one)

step 3: make another ground wire. (doesn't have to be to the same point)

step 4: split the remote turn on wire off the other amp. (splicing in is fine, no power is drawn from that wire.)

Then ofcourse you need to run the obvious wires (RCA'* and speaker wire)

caps are crap IMO. they are a very poor band aid / attempt of a bandaid for a weak electrical system. If you get dimming you need to complete the "Big 3" (a search will yield you all the info you need to know about that), and possibily a better battery/alt combo. If that still doesn't really fix your problem then you will likely need to upgrade the 4ga going from the front to the back of the car to something larger to handle the load. This assumes that you have very clean and solid ground connections, which alone can cause issues.

After all of the checks are done to find out what you blew, it may be a good idea to adjust your gain setting properly if you have not done so. Poor gain settings (too high) can cause speakers to blow and amps to clip which is very very bad.

I did the swapping RCA cables around today, the rear speakers do not work at all.
Both of them
The both blew at the same time?!

Are you driving them off an amp that might have had an issue?

Did you check to see if the rear channels from the amp will push the front speakers? Sometimes you will find that BOTH the amp and the speakers will go at the same time...

I put the stock 6x9s back in, and they work wonderfully, hell, they sound EXCELLENT hooked up to that amp, the MBs have failed.

warrenty??

im gunna try for Warranty.