ohm meter to test wiring

[Ron Dickey]

I found one side did not work so I checked it with a Ohm Meter and found no mater which wire I checked they all showed that wires were all interconnected. in a trailer where in the light all is grounded to the same thing does that mean an ohm meter is no help??

Or does this mean two wires are touching where they "ain't" supos ta??

How do you test your wires??

Ron D.

[asianflava]

Which wires are you testing?

Speaking in general terms, if you have 2 wires that you want to test that are bare ended (not connected to the load)

Use the Ohm meter to test the - to the frame, it should show continuity (if you have it hooked that way).

Use the Ohm meter to test the + to the frame, it should NOT show continuity.

With the power off, use the Ohm meter to test the + to the -, it should NOT show continuity.

You should test the + to - with a volt meter. Turn the power switch on and off. The voltage should show up and toggle on and off with the switch.

[sdtripper2]

Ron:

There are a few bits of data unknown in your problem as you pose your
question. When you say side I am not sure what you mean? Please show
pictures or explain in more detail ... I am sure these guys can help, but I
will throw out a few thoughts now to get you thinking.

The hot side of the side of the fuse should not be at a ground potential.
So while using a ohm meter there should be some resistance or ohms
difference from one side to the other but ground should read "0" = zero.
The hot side should not read "0" = zero when you touch one lead of the ohm
meter to ground and the other to the hot side of the taken out fuses on the
Block you have on your panel.

Remember a light bulb will have a low resistance Example .05 ohms. if you
test across it out side the circuit you will read some amount of ohms. To
test if for example the outlet has a short.... take the light bulb out of the
circuit and touch the ohm meter to ground on one lead and the other lead
to the hot side of the circuit leg. This should so an OPEN or no short where
the digital dial goes does NOT show .0.0.0 or the analog needle doesn't
swing all the way to read "0" = zero.

So to do this test NO POWER Should be present on your DC Circuit at all
while running these ohm tests.

The grounds to your panel should all read = zero ohm where the meter dial
shows a change to Zero.

The hot sides of your circuit should not read like the ground circuits but
depending on the load IE light it will read some resistance but NOT Zero or
= to ground.

If you have some extra wire you can test say an inside dome light by
attaching a long length of wire to each end of the wires one at a time and
touch the other end at your box with the Ohm meter in the center and
there should be "0" = zero as the dial changes you should NOT SEE bars
for a digital meter = "- .-.-" or the analog meter should swing over to Zero
NOT STAY in its resting position.

I am sure these other guys will come and clear this up if you still have a
problem with my description.

[Dale M.]

Actually a volt meter may be easier to use.... Its either voltage preset or no voltage present (most cases) in these situations....

Generally one looks for voltage in reference to a "common ground"...

Ohm meter indications can be elusive because you can get feed back resistances reading through other light bulbs in circuits and other conditions...

There are many good tutorial on using volt/ohm meters on Internet...

My favorite tool is just a simple $3 test lamp for 12 volt circuits ... Available at any auto parts store...

Dale

[Ron Dickey]

Thanks guys fixed it.

lower Trailer done except for small things.
Now I need to wire truck to pull and off to DMV to get that part licensed. In Jan but I may wait until Feb. so I do not have tags in the same month.

Anyway no pix till next year Murphys law still in affect there but I am working on it.

Ron

[sdtripper2]

Ron:

What was the problem that you fixed and how?