Milligan Auto Diagnostics tackles a dead wiper system on a 2017 Mercedes Sprinter after a reverse-polarity jump start destroyed the vehicle’s SAM module.
With the van’s battery sitting below two volts, the technician insisted on fitting a fresh battery and maintainer before installing the £400 OEM body control unit to prevent damaging the new hardware.
After stripping the glovebox and lower dash trim using long T25 Torx bits, the damaged SAM was unclipped. Commissioning was carried out using Mercedes Star diagnostic software to complete initial startup, SCN coding, and VIN registration.
Post-repair teardown of the old module revealed two eight-pin driver ICs had burned out, which had cut the output signals to the external relay controlling high and low wiper speeds.
