I am working on 1991 300E 4matic ABS . I disconnected the round abs front sensors connector and hooked my DVOM up to the sensor end . Set the meter to 20 volt AC and tie strapped the meter to the wiper. I drove on the road at 70 km per hr . right sensor read .91 ac volt, left sensor .94 ac volt . unhooked rear flat connector under seat read 1.84 ac volt . What I need is the correct ac voltage from a working system from same 4matic . I can change my voltage by decreasing or increasing the air gap. Could any one please help? Dale