Question about grounding measurements
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Question about grounding measurements
Yesterday cleaned four grounding points on engine bay, are there any other or just four?
Today measured with ohmmeter, the strange thing is i'm getting two measures
Engine off ground points value are in good range about 0,5 ohm, same pointing engine block
Though when turn on engine, idling in neutral, same points resistance became 3 ohm.. Would assume that this is normal 'cause many parts are in movement and absorb current but i'm not sure...
Today measured with ohmmeter, the strange thing is i'm getting two measures
Engine off ground points value are in good range about 0,5 ohm, same pointing engine block
Though when turn on engine, idling in neutral, same points resistance became 3 ohm.. Would assume that this is normal 'cause many parts are in movement and absorb current but i'm not sure...
Melting Slicks
Joined: Jan 2008
Posts: 2,054
Likes: 120
From: AZ
I learned, when chasing stereo noise, that different frame points have different ground values. In audio, that causes ground-loop-induced noise. Often, what some think is (+) side noise, is actually a grounding problem, solved by using ONE ground point for the audio.
With your measurements, current flow through the wires probably effects the differing indications. .5 vs 3 ohms doesn't seem like a problem to me and may fall within the meter's range of error or how solidly the probes are touching the test points.
Then, there are better e-wizards here than I am.
With your measurements, current flow through the wires probably effects the differing indications. .5 vs 3 ohms doesn't seem like a problem to me and may fall within the meter's range of error or how solidly the probes are touching the test points.
Then, there are better e-wizards here than I am.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
I learned, when chasing stereo noise, that different frame points have different ground values. In audio, that causes ground-loop-induced noise. Often, what some think is (+) side noise, is actually a grounding problem, solved by using ONE ground point for the audio.
With your measurements, current flow through the wires probably effects the differing indications. .5 vs 3 ohms doesn't seem like a problem to me and may fall within the meter's range of error or how solidly the probes are touching the test points.
Then, there are better e-wizards here than I am.
With your measurements, current flow through the wires probably effects the differing indications. .5 vs 3 ohms doesn't seem like a problem to me and may fall within the meter's range of error or how solidly the probes are touching the test points.
Then, there are better e-wizards here than I am.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Resistance measurements must ALWAYS be done with no electrical current in the circuit being tested. The ohm meter must provide the only source of electrical current thru the circuit being tested. That's why there is a battery inside the ohm meter (digital or analog).
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Resistance measurements must ALWAYS be done with no electrical current in the circuit being tested. The ohm meter must provide the only source of electrical current thru the circuit being tested. That's why there is a battery inside the ohm meter (digital or analog).
