please help. Radio trouble

Earlier today i ran a set of amp wires. After i got finished i took the radio out to put the rca's in. I connected the wires back to the radio and I am not getting anysound from any of the speakers not on the amp. the radio is fine. It turns on and the memory wire is fine because when i turn it on and off it picks up where it left out. I have never had this problem before. None of the speakers are coming on and I even tried with a different radio.

[meissen]

The radio turns on, does the amp turn on? How many speakers is the amp powering, all 4 in the car, rear two speakers, or a sub?

[Xavierz28]

The amp is just powering the rear two speakers. I got the radio to work. The problem was the car has factory amplifier and I hadn't plugged the signal wire in. Since the factory amp has not been bypassed it had me confused. But I got a new problem. The speakers that the amp is on keep giving off an high pitch noise. It doesn't do it if the car is running on auxilary but soon as you turn the car on the noise comes. What should i do?
i checked the ground and it is fine

[MrMojoRisin681]

I believe that is alternator noise, or noise from wires running too close together.

[Xavierz28]

i will re do the wires tomorrow. The high pitch noise is coming from the speakers tho. I can get rid of it by turning on the low pass filter but then you really can't heat the speakers.

[archemedes]

that is from a bad ground 99% of the time it's alternator whine, if you have a factory head unit it will happen with teh conveters, get a good ground loop isolator and it will help