Ok I have 2 capacitors in parallel and a diode in series I think on the positive line im feeding them with a 12v battery but now if I unplug the battery its outputting 2volts but is the diode not supposed to stop reverse voltage?
I drew a quick picture on paint so forgive how it looks
Your diode will have a reverse leakage current of a few microamps. If you're measuring voltage with a digital multimeter it will have a high impedance so it will take very little current to give a reading on the voltage range.