Charles; The way I understand it is this: Below 2000 rpm the dynamic oil-pressure system checks the output of the 4.4psi for an OPEN circuit. This signifies enough pressure is present to OPEN the switch. If a switch closure IS detected the LED flashes. Above 2000 rpm the dynamic oil pressure system stops looking at the 4.4psi switch and starts looking for a switch CLOSURE from the 13.1psi switch. If a closed circuit is NOT detected the LED flashes and the buzzer sounds. The circuit is NOT designed to warn of too much pressure, only enough pressure at two rpm ranges. Reference Bentley pages 17.10 and 90.24

Good Luck Ken Lewis kdlewis@juno.com 86 VW crewcab 85 VW Vanagon GL 60 356 coupe

On Fri, 3 Jan 1997 10:31:02 -0500 cbennett@kpmg.com writes: >Thanks for the explanation regarding the two oil pressure switches. >You said >that the 13.1 switch must close with RPM greater than 2000, and if not >the >flashing LED and buzzer occurs. Does this mean that the switch is >measuring too >high pressure? I would assume that when you say the 13.1 switch >closes, it >completes the circuit and the LED flashes. I am still unclear whether >or not >the two switches measure too low and too high oil pressure. > >Charles >