- Location
- Rainy side of Washington
that is odd, I thought the heaters were always 12 volts and the sensor side was always 5. Running the heater off 5 volts seems wrong, because that large a current draw will cause a voltage drop across the harness and skew the computer's idea of the rest of the sensor readings.Update. I discovered that the feed voltage to the O2 sensor heater on my 89 is only 5 volts, not 12 volts like my 87.