Need help with Replacement Stereo

[mbfree66]

I have a 03 Cherokee Trailer Trailer that the Concertone stereo has never really worked. I am replacing it with a car stereo. When I connect the car stereo to the wiring that connected the Concertone stereo, I can not get it to power up. I checked the car stereo with a ac/dc converter and it powered up fine. I checked the volts on the wiring and its at 10.4 dc volts. Is my problem not enough volts and if so, how can I get it to 12 volts? Any help would be appreciated.
Thanks

[backin15]

10.4 is pretty low. If you are not on shore power are you sure your battery has a good charge? If so try checking the voltage at another 12v power source, like a light. If it has 12+ volts look for a poor connection at the radio wiring. Good luck!

[mbfree66]

I will check at a light connection. Actually I am connected to power outlet.
Thanks