ejforwood
Littleton (Denver) Colorado
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Joined: 04/26/2006
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hwybnb wrote:ejforwood wrote:
This example is in series, and you are checking for the flow of voltage. In order for the meter to register it has to be connected to a + and a -. If there are no other circuits turned on the voltage will read 0 because it sees only the + side. If you turn on a circuit, light or whatever, you have now supplied the - and the current will flow. Nope.
First, voltage does not flow. Current flows.
With the cable disconnected from the battery the voltage between the battery and the cable will ALWAYS be zero, no matter if a circuit connected to the cable is on or off. The meter will not complete the circuit if it is on the voltage setting.
You are correct.I typed the wrong word in the first sentence. Note, I typed the right one in the final sentence.
As to the rest of your post, Are you sure? Have you tried it?
Jerry, Dottie & Chan, "the little furry one"
98 Bounder 34V, 99 F-53 Ford V10 chassis
06 Saturn VUE 4I
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3huskies
White Mountains, NH USA
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Joined: 07/18/2003
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bsprague wrote:The OP seems to be trying to measure current flow at the battery terminal. There is an easy way. Buy one of these from Sears: DC Clamping Meter.
Note that it is rated for DC or AC. Many are AC only. Check specs on the package before you buy.
NO...Again, just trying to figure out if you can use a multimeter on the DC VOLT scale connected in series as stated above...I know what amps/current is and how to measure it which, by the way, is the way I would do it.. I have a Fluke 179 that goes to 10 amps with a Fluke ac/dc accessory clamp that goes to 400 amps so no problem there..
"ejforwood" seems to confirm what the book is stating
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hwybnb
Southern California
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Joined: 05/02/2001
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ejforwood wrote:As to the rest of your post, Are you sure? Have you tried it? Yes, I have tried it.
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ejforwood
Littleton (Denver) Colorado
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hwybnb wrote:ejforwood wrote:As to the rest of your post, Are you sure? Have you tried it? Yes, I have tried it.
And your results were?
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Hurricaner
Hurricane Utah
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Joined: 02/17/2007
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RCL had it partially right but you will see 12 volts if there is a complete circuit and 0 if not. The meter on the voltage scale has too high of resistance for a load to power through it, but if you make a mistake and have it on the ohm scale you could have big problems. Here is another multimeter tutorial http://mechatronics.mech.northwestern.edu/design_ref/tools/multimeter.html
Sam
Sam & Kari
Hurricane, Utah
2004 34' Damon Challenger 315
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Rvpapa
Alberta , Can.
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Joined: 08/07/2002
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3huskies,
The short answer to you question is "yes". It is a creative way of looking for a phantom load that secretly drains your batteries when you are not looking. When you disconnect the positive battery cable and put your meter in series on the VOLTAGE scale you are in effect using any circuit in the RV that happens to be turned on as your negative path. This is much easier to look for that ghost that kills your batteries over a couple of weeks.
Art.
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3huskies
White Mountains, NH USA
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Thanks Rvpapa...Can you also check for voltage drop using the dc scale in series? For example a probe on one side of a switch, let's say, and the other probe on the other side of it... So again you are putting the meter in series on the dc scale are you not?
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Rvpapa
Alberta , Can.
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Then you would be in parallel with the switch, but that will do what you are asking, reading the voltage drop across the component. This will require a fairly sensitive meter (read also expensive) and preferred an auto-rangeing one because you need a low voltage scale to read a very small drop, but if you forget and open the switch with the meter connected you have full circuit voltage on the probes as you are now in series in the circuit.
Art.
on edit this is if you are checking the voltage drop thru the switch contacts.
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plauterer
Manitoba, Canada
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Joined: 08/29/2004
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What you see in the book is correct. The meter is connected between the pos post of the battery and the connector that is normally connected to the post. a reading of 12 volts will indicate that something is competing a circuit back to the negative side of the battery.
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btraptormd
Virginia
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Joined: 11/11/2007
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My head is spinning after reading all that but finally Rvpapa got it correct. The test hooking a volt meter up in serries is not used much anymore because it is not very helpful. In modern automobiles there is enough normal load that you will always show 12v. Most of the time if you are trying to find a drain on the battery you will set your meter to amps and hook up in series as stated in previous post. If you want to check a voltage drop across a wire, switch, fuse, or any other item in the circuit you set your meter to dc volts and hook up in parallel across the component you wish to test. With the circuit energized your meter will read the voltage lose across that component. This test is very useful for checking battery cables,relay contacts, and connectors.
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