O2 sensor ohms

Well, I have the dreaded engine control fuse blowing problem. I have searched but I have not come across the info that I am looking for.

I have the factory service manuals for my Cherokee.

What I have done;

-Pulled fuel pump relay, fuse blowing stopped.
-Pulled fuel pump module, tested fuel pump and it works fine.
-With a Fluke 112, I checked ohms to ground from connector of PDC for fuel pump relay that goes to fuel pump wiring and get 4 ohm reading (almost a dead short). I then switched to the amp reading mode in the 112 and blew the 10 amp internal fuse in the meter by reading from the 12v connector to the fuel pump wiring connector in the fuel pump relay socket.
-Disconnected main connector inside left kick panel, disconnecting all rear body wiring, including fuel pump wiring. Still get 4 ohms in PDC to ground.
-O2 sensor is brand new Bosch, only about an hour of engine run time on it. O2 sensor power is on fuel pump power wiring. Disconnected it from harness and now I lost the 4 ohm to ground.
(I have actually done much more diagnostics but I am just keeping this short for brevity)

Question is, is the reading for the O2 sensor heater element normally approx 3-4 ohms or is this my short that is blowing my engine control fuse?

Are you following the basic trouble shooting test procedures at the beginning of Section 8W of the FSM ? You should first be checking for continuity of power and ground, then cross checking the same wires for short circuits. Test for voltage potential, and for voltage drop. Next test for voltage where there should be no voltage.

Yes, I did, and unfortunately, there is no trouble shooting guide in the beginning of section 8W in my FSM. Plus I am just a slow typer and was trying to keep it short and to the point. If I typed everything that I did, I'd be here for and hour and a half, lol.

Very simple really, and I have been using the FSM wiring diagrams the whole time.
-engine control fuse blowing.
-pulled fuel pump relay and stopped blowing fuses.
-Pulled fuel pump and tested, it works fine.
-With fuel pump unconnected, reinstalled fuel pump relay and still blowing fuse.
-Unplugged main connector in left kick panel that has fuel pump wiring to isolate whether the short is in the engine compartment wiring or the bulkhead back wiring, still blows fuse. Obviously problem is in engine compartment wiring.
-Checked continuity from connector for fuel pump wiring in fuel pump relay connector to ground at battery and I get 3.5 ohms (minus the internal resistance of the meter and probes, it would be slightly lower), almost a dead short and enough to pop the 10 amp fuse in my Fluke 112 meter while testing amperage draw in that circuit.
-Wiggled all wiring in engine compartment (that fuel pump and O2 sensor power wires run through) while watching meter and no changes.
-Finally, unplugged only other thing that is on same power circuit as fuel pump, the O2 sensor, while watching meter and meter goes to OL, infinite resistance, no continuity.
O2 sensor is brand new, wiring is perfect, nowhere near anything that can harm it.

Process of elimination.

I just need to know if 3.5 ohms is the correct resistance of the O2 sensor's heating element. If it isn't the correct resistance, then I found my problem. If it is correct, then I have to look elsewhere for the problem.

A 98 & 99 FSM shows ..

Between the white wire terminals of the harness plug connector.

Resistance should be between 4.5 and 7 ohms (+/- .5 ohms)

Replace the sensor if the ohmmeter displays an infinity (open) reading

Thank you for your response and I do really appreciate it. My only problem is that the '96 and up have different part numbers and I'm not sure that they would have the same readings, they might, but I'm not sure. My XJ is a '91, see my sig below.

Where did you find that info in your FSM? Maybe it is in mine also, I just can't find it.

Try searching for "OXYGEN (O2S) SENSORS", "O2S heating element" & "Oxygen Sensor Location".

Oh, ok, thank you. I have the old fashioned turn the pages kind of FSM, lol.
I'm still looking for it though. I have a 2 book FSM and I'm thinking maybe there was a 3rd book with the trouble shooting and O2 sensor specs in it.

The OXYGEN (O2S) SENSORS is located in the Fuel Injection Index.

I found paperback and cd manuals from https://www.techauthority.com/en-US/Pages/Home.aspx

Most of my Jeep manuals (paperback and cd) cover 97, 98 & 99.

I have an older Chilton manual on CD (84 - 01), but could not find any resistance specifications, if I come across any test specifications will post them.

Rock Auto carries FSM Jeep, Haynes & Chilton manuals .

Heater resistance cold is 5 ohms.

Thanks guys! The answer is 5-7 0hms. I found the specs in a small paragraph buried in the middle of the fuel systems section of the larger of the 2 books entitled "Engine, Chassis and Body" while the wire diagrams and all the electrical stuff is in the other book "Electrical, Heating-AC and Emissions". Weird, I would have thought they would have kept all of the electrical stuff together, no wonder I couldn't find it.

Soooo, obviously my O2 sensor is bad, dammit. It's brand new but I can't return it. My XJ has been off of the road since spring due to upgrades that I've been doing to it and that is when I bought the 02 sensor. Oh well...