Hello, good day My car battery has emptied itself a few times because of a short circuit. Until I bought a new one, I bridged a few times battery. One time it went back because I unfortunately + and – confused in the dark and since despite a new car battery my self-built Navi/Autoradio no longer goes. I checked all fuses in the car and they were in order… . The car radio gets 14,1 v voltage in idle and 12,8 when it is off… but navi does not work anymore. Then I bought a new car radio and with the new one it runs the same way. But I noticed that with the new under details it stands that it works with dc 12v dc (there is not 12v to 14.4 v) … can it be that it is the reason? Is 14 v voltage on car radio with 7 inch screen with 4x55w output power too much? Or what else can everything have been broken? Thanks in the presus ? Ps The only difference between the two connection lies with the cable tree