Wierd electrical issues...

[rsmithdrift]

Ok, I was trying to volt test my 02 sensor and found it to be impossible...

I was finding that no matter where I put the voltmeter while the car was running it would read some voltage, even if I wasn't touching anything that's supposed to have voltage.

Example: If I touch the red lead to the block and the black lead to the strut tower bolt I get a reading of 0.34 - 0.50v... If I just set the voltometer on the top of the engine I get a reading of 1.15v. If I touch the red lead to any part of the car and hold the black lead in my fingertips I get a reading of 0.34-0.50v. If I touch the black lead to the ground on the battery and the red lead to any part of the car I get between 0.5 and 1.5v

It's the strangest thing I've ever encountered. I don't think it'd be possible for me to get an accurate read on my 02 sensor with the voltometer giving such odd readings... And it's not the voltometer's fault, it works perfectly.

The other thing is I tried to check my knock sensor and I couldn't get a reading in ohms, I think it should be between 650 and 700 at 75*, but when I unplug it it makes the car run significantly worse.

[Vegascorbin]

Example: If I touch the red lead to the block and the black lead to the strut tower bolt I get a reading of 0.34 - 0.50v... If I just set the voltometer on the top of the engine I get a reading of 1.15v. If I touch the red lead to any part of the car and hold the black lead in my fingertips I get a reading of 0.34-0.50v. If I touch the black lead to the ground on the battery and the red lead to any part of the car I get between 0.5 and 1.5v

Not as strange as you think. #1 make sure the voltmeter is set to DC not AC.#2 don't worry too much about what you read until you have the leads set in the proper place.#3 if you are reading up to 1.5 volts from the battery negitive terminal to the frame then you have a bad ground. Check all of them and then re-test. A bad ground will throw all your readings off.#4 also be sure that you are connecting the Black lead to the negitive or ground and the Red lead to the signal you are trying to messure.

Fix your grounds and I am sure you will get better readings.