Car Radio turning On and Off only when engine running (Bad grounding?)


Joined Jan 23, 2018
Now I see that the TS has to re-connect the alternator so that the battery will charge. So now we know that there are assorted "issues" with the car electrical system. So I ask the same questions again. Where is the power supply wire connected???

Thread Starter


Joined Apr 23, 2020
What I have not seen is how the radio plays when the engine is not running. That is something that we should know. It might be that the radio is connected to a totally incorrect circuit. That cycle sounds more like a steering wheel heater circuit. The radio should connect to the accessory feed off the ignition switch. If the car is one of those with just a stupid start/stop button, then the radio should connect directly to the battery, with a suitably rated fuse. Consider that it might be the power feed switching on and off. It might be a current limited circuit thinking that the radio is an overload.
i will give more information

The vehicle is an old Argentinian truck, it didn't have radio, i fully routed the wire harness, the ignition swich is a barrel one, going clockwise: ACC, OFF, On, Start (with spring),

The radio is connected to an off 12v supply and an acc/on 12v supply, when the engine is not running, the radio works perfectly
I attached connections and videos



Joined Jan 23, 2018
OK, A simple check will be to connect a low power 12 volt light to that same "ACC terminal and the same common connection as the radio. If the light blinks then it is not a radio problem.
one step would be to temporarily connect the radio power feed line to a fused direct connection to the battery positive. With the connections described I am suspecting that switch,