Hello, have bought a Womo Sprinter 318 CDi Built in 2007, first release only in 2014. Used Fz 2016. Starter battery 100Ah 810 Amp (En) brand new. Voltage is 13,3 V. Starter battery in the footroom in front of driver’s seat is exposed and voltmeters are clamped. E-Box is switched off (which controls the living area with supply battery 100Ah / 810 Amp (En)). When plugging in the ignition key and turning to the first level all symoble are correctly displayed. Vorglühsymobol also extinguishes. But voltage breaks down to 11.8 V and climbs slowly again to 12.3 V. Ignition keys turn to start the starters. Starter keys do not track. Just a click of the starter relay is to be heard. Starter relay has already been exchanged against a new one. How can I find out which component causes the voltage drop? Greeting Axel PS: I clamp a CTEK 5.0 charger over the remote start point and waits for the starter battery 14.