So my alternator quit charging. According to the manufacturer trouble shooting procedure my alternator and regulator are good. If I jump 24V to the ENG term on the regulator everything charges fine, which says regulator and alternator are functioning as advertised. My oil pressure reads good at the dash and the Oil Pressure light goes out when the pressure comes up. All seems good. The small schematic on the Niehoff troubleshooting guide shows a switch between batt power and the ENG terminal on the regulator. Is this the oil pressure switch? If not what/where is it, and if it IS how can I troubleshoot the wiring between it and the regulator without tearing the harness apart between them? I'd rather avoid that given this models rep for iffy wiring. Are there multiple wires coming off the pressure switch that would allow good signal to instrument panel/gauge, but bad signal to ENG term on regulator?