Car stereo has not sound. Panel lights up, cd indicates it is playing but NO SOUND?
In some newer cars all the speakers are run off of a stock amp....in the wire harness adaptor that you installed check to see is there is a amp remote wire that needs to be hooked up to 12+ volt source to turn the amp on.
My car stereo is on but there's no sound coming out
Double check the wires, you thought were for each speaker. There may be a common wire for a set of two speakers. When you state "it works" are you basing it on the fact the dial light comes on...the lights are on a separate power circuit.
Check your fuses before you do anything that is a simple and cheap fix and most of the time is the problem, especially in 90's model and older cars with aftermarket stereo systems.
Did you install a harness adaptor. If so you may have a factory amp located somewhere in the vehicle and you will need to bypass it.
Dial light comes on speakers are working, there's just no connection
Check if there are any wires touching the chassis of your vehicle or if there are some touching each other.
I am sure that the problem lies with the wiring of the stereo system. You need to check each and every wire of the new system. If the problem continues then try out the audio functions of the PRE. I hope they have a warranty.
Get an professional to come and do the job, this is not something a regular person with no experience would be able to do.