oxygen sensor connectors

[ambyrell1]

My connectors got melted on my 93 Tercel, does anyone know which wires go together, color wise?

[noahthefrog]

Wires are usually color coded to match. Yellow plugs into yellow, green into green, etc. On my '89 the oxygen sensor connector is gray, but I don't know if it's the same on the '93.

[bkftl]

http://www.aa1car.com/library/o2sensor.htm

Heres some info, theres a wiring chart on there, it might be for 4 wires and tercel has 2 but u can match the wires still. It also tells what they do.

[ambyrell1]

Originally Posted by bkftl

http://www.aa1car.com/library/o2sensor.htm

Heres some info, theres a wiring chart on there, it might be for 4 wires and tercel has 2 but u can match the wires still. It also tells what they do.

thanks for that info, now do you know how I can tell which wires does what on my engine wiring harness? I have a black one and a brown one, with the link you provided I now know the Blue wire on the oxygen sensor is for signal, the white is ground. So, would the black wire on the factory harness automatically be for ground?

[noahthefrog]

Oxygen sensors usually ground through the exhaust manifold's metal, like spark plugs do. If you have two wires, probably you have a heated plug (so it works when engine is cold).

I'm not 100% sure, but I think the one that is for the heating element coming from the wiring harness will put out 12v+ when the engine is cold. The signal wire coming from the oxygen sensor should put out 0.5-1v+ when the engine is revved, assuming the sensor is not faulty. Some experimenting with a multimeter should shed some light on what's what.