99ls1tj

I'm rewiring my rock crawler. The motor is a 2000 ls1 from a camaro. I'll admit, I probably know just enough to be dangerous.

I ran across this issue accidentally. It may be normal, but it makes no sense to me.

If I have one of my o2 sensors plugged in, I am getting continuity between the 12v pink sensor wire and the ground wires in my harness. I was using the pink wire from the MAF sensor for testing.

I made a little video just to try to clarify how I was testing. As soon as I unplug the 02 sensor, I lose continuity. At first I thought it must be an issue with the o2 sensor wiring, but I've tried 3 different sensors and they all react the same.

It seems to me this would cause a short to ground if I put 12v on the pink sensor wire.

Thanks



http://youtu.be/IVBA6taFToo

99ls1tj

Actually, on closer inspection i'm getting 4 ohms resistance (assuming I'm reading my meter correctly).

i r teh noobz

iTrader: (4)

Video is private.

Pink wire should be for the heater circuit and should ground through the sensor when plugged in. Not sure what the resistance spec is.

99ls1tj

Thanks for clearing that up! I attempted to change the video to public.

99MUSTANG5.3L

I was gonna mention the low resistance readings but you figured it out. What exactly is the issue you're having(I didn't watch the video if mentioned).

99ls1tj

No specific issue, I was just verifying some connections and was surprised to see my meter was giving a continuity tone between the power and ground wire on the o2 sensor since the MAF uses the same power wire. I guess I thought I had a short somewhere. Thanks

soundengineer

iTrader: (16)

This should help





and it does not ground thru the sensor...it grounds thru the pcm

LS1MCSS

iTrader: (18)

Here's the schematic for them, in case you need it. It sounds like you have a short somewhere in the harness.

99ls1tj

Thanks for posting the schematics! I don't think there is short in the main harness, because I only have continuity when I connect the harness to the o2 sensor. To be honest, I'm getting more confused. When I read i r teh noobz's post, I thought I was alright. Now I'm getting concerned I'm going to fry something.

i r teh noobz

iTrader: (4)

The schematic posted above clearly shows the pink wire going through the heater circuit and then to chassis/engine ground. I would expect there to be some continuity there if the MAF positive wire is shared by the O2 heaters.

Measure the resistance of the sensor heater. See if its close to the 4 ohms you're getting.

Do all 4 O2s act the same?

LS1MCSS

iTrader: (18)

Bolt those ground wires to the back of the head, the way they are supposed to be. Plug in the O2 sensor and then try the test again, just grounding the meter to the engine block. Has there been power connected to the harness yet?

99ls1tj

I only have 2 o2s, the rear ones have been deleted. I also have one on my bench that had been replaced some time ago because I was not getting a reading on it from my scan tool.

All 3 sensors I've checked are showing approx. 4 ohms. If I have both o2s plugged in and check resistance between the maf positive wire and ground I'm getting approx 2 ohms resistance.

Thanks

99ls1tj

Did that, see post right above this one. No power since I've re-wired it.

Thanks