O2 Wiring Fire

[North Coast Cab]

I had a small electrical fire around the wiring from my O2 sensor. Three wires come out of the O2 sensor. One goes to the yellow round connector in the picture. The other two go to this power connector which is held in a bracket next to the round yellow one.

The two conductors melted the insulation and most of the outer jacket back several inches form the connector. I sliced open the harness section as far back as I could and it looks like like the rest of the harness is ok. So, does anyone know where these wires go? I'd like to just bypass them and run two replacemnt wires, and I'd prefer to know where they go rather than drop the the engine and follow the harness until I find out.

Any help would be appreciated. I have a lapping day at Mid Ohio on Wednesday so the timing is terrible.

John

[North Coast Cab]

Anyone? My alternative is to drop the engine and cut open the harness. Kind of desperate.

TIA, John

[North Coast Cab]

Anyone, anyone?
Ok, the motors coming down tonight.

[North Coast Cab]

It''s crazy, but this piece of the harness and two others about the same size go under the cruise module and then around behind the strut top. Only two of the harness sections reappear behind the engine. So, does anyone have a motor out that could verify this? Could the one harness, the one I'm tracing, go into the interior from here? Where could the two white O2 sensor wires go?

John

[North Coast Cab]

I'll keep the thread going all by myself.
I got the harness open and inspected everything down below. What I need is someone to tell me the colors of the two wires in the black square connector shown above. It's the one to the left of the round yellow connector which the white O2 sensor wires connects to.

John

[rick-l]

I don't know if this will help or not. I have the Factory service manual but it is not very rich with info.

SN 62? is a connector labeled Oxygen Sensor Heating.

There is a brown .75 dia wire that goes to a point labeled engine ground (SN58?).

There is a yellow .75 dia wire that goes from the heater to the DME relay terminal 87b. 87b also goes through a fuse and then to the fuel pump.

It appears the OXS heater is unfused. Lucky you didn't have a major fire.

SN73 ( again whatever that means) looks like a shielded wire that goes to the sensor itself.

[North Coast Cab]

Thanks. That makes sense since the two wires on the connector are a dark yellow or brown. I traced the yellow wire into the harness towards the DME so hopefully I can remove and replace.

John

[rick-l]

Thinking about this some more I would be very concerned over the state of the wires in the wire harness going back to the DME.

I also think the reason it burned up was the fact there is no fuse in the circuit. If you don't have the problem sorted out I would add a fuse inline under the drivers seat.

Funny that in a very high end sports car like this the Pooshey engineers couldn't see fit to spend the extra 50 cents to fuse a circuit that goes into the engine compartment and sits on the exhaust pipe.