Oxygen sensor voltage

[just-n-time]

In testing my heated ox today I turned on the key and when I tested the voltage at the green wire it started out at 11.5 and steadily dropped to around 1.3, why. 1990 190E California car.

[porkface]

sounds like the heater circuit is shorted with the sensor wire. replace the o2 sensor. good luck, chuck.

[just-n-time]

Originally Posted by porkface

sounds like the heater circuit is shorted with the sensor wire. replace the o2 sensor. good luck, chuck.

the wire to the heated section is what i was refering to. thats the wire from the car to the ox. i wonder if it goes threw a fuse or a relay.