Originally Posted by cass944
Yes, Voltage is not the only thing that matters when powering something, amperage is equally as important.
Tell us more about your setup please, but undoubtadly, if you are trying to power the carputers DC-DC with an AC-DC wall supply, it is too small and won't do it. I would suggest you stop also, before you have a fire.
The "wall wart" probably has a rating on it, like 12 volts, 1000 MA or something like that. That means 12 volts and 1 amp. You need about 15 amps or so to power your carputer. You will need a special DC power supply for that, something like this http://www.mfjenterprises.com/produc...rodid=MFJ-4322.