At127

Hi,

I recently bought a 2006 E350 and suffering from the mysterious battery drain. I replaced the main battery and it drained in 1 day. The auxiliary battery reads at 12 amps. Is this an issue with the voltage regulator or the battery control module if only the main battery is draining?

rapidoxidation

or a seat controller or a radio or a window switch or.... automotive electrical diagnosis isn't easy but it can be done methodically.