Using my new multi meter
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From: Portland, Oregon
Using my new multi meter
I know this will seem pathetic to some, but I am hoping someone who understands the electrical stuff can help me. I am clueless, but would like to learn. I got some new plug wires, (magnecore) and was told I should test them before I install them. Can someone tell me:
1. What I am looking for?
2. What am I testing?
a. Resistance?
b. Volts?
c. Amps?
3 After that is cleared up, how do I do it?
In trying to test for resistance, here is what I did.
I connected the red lead of my meter to one end of a plug wire and the black lead to the other end. The black lead is plugged into the COM port on the meter and the red lead is in the V/Omega port. No matter where I put the scale with the rotary **** on the meter, all I get is a 1. Which according to my tiny instruction book means it is reading outside the scale. The scale is 200, 2k, 20k, 200k, 2m, 20m, 200m. All in the area marked with the omega symbol. The one that looks like an upside down U with feet.
Can someone offer some guidance?
Thanks,
1. What I am looking for?
2. What am I testing?
a. Resistance?
b. Volts?
c. Amps?
3 After that is cleared up, how do I do it?
In trying to test for resistance, here is what I did.
I connected the red lead of my meter to one end of a plug wire and the black lead to the other end. The black lead is plugged into the COM port on the meter and the red lead is in the V/Omega port. No matter where I put the scale with the rotary **** on the meter, all I get is a 1. Which according to my tiny instruction book means it is reading outside the scale. The scale is 200, 2k, 20k, 200k, 2m, 20m, 200m. All in the area marked with the omega symbol. The one that looks like an upside down U with feet.
Can someone offer some guidance?
Thanks,
Pro
Joined: May 2003
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From: SF Bay Area
You would be looking for resistance. I don't know what level is acceptable. Your technique sounds ok.
With the meter set on resistance, touch the red and black leads together. This should read zero ohms as there is no resistance between the two leads. You used to do this to older voltmeters to calibrate them. Then take them apart and notice that the resistance is infinite or out of range.
You can try measuring any piece of metal - wires, coat hangers, paper clips, crecent wrenches etc just to get a feel for how to use it.
Next touch the black to one side end of the plug wire and red to the other. You should get a very low number. Someone else can chime in as to what is an acceptable value.
With the meter set on resistance, touch the red and black leads together. This should read zero ohms as there is no resistance between the two leads. You used to do this to older voltmeters to calibrate them. Then take them apart and notice that the resistance is infinite or out of range.
You can try measuring any piece of metal - wires, coat hangers, paper clips, crecent wrenches etc just to get a feel for how to use it.
Next touch the black to one side end of the plug wire and red to the other. You should get a very low number. Someone else can chime in as to what is an acceptable value.
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Joined: Apr 2004
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From: SW Ohio
Joe,
Do you have to flip through the scales yourself? On mine, I have to move the decimal point using the scale button to get a reading. That is, if I were trying to measure 120 VAC and I had it on the scale for milivolts, I probably wouldn't get a meaningful reading until I flipped through the hundredths, tenths, single digits and tens digits scales to the hundreds scale. Just a thought.
Do you have to flip through the scales yourself? On mine, I have to move the decimal point using the scale button to get a reading. That is, if I were trying to measure 120 VAC and I had it on the scale for milivolts, I probably wouldn't get a meaningful reading until I flipped through the hundredths, tenths, single digits and tens digits scales to the hundreds scale. Just a thought.
Pro
Joined: Jan 2002
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From: Cape Town
Joe
Sounds like you're doing it right but your meter may have a fault. (Battery?) The upside-down U with feet is the 'Ohms' character. Symbol for resistance. I don't know what the value should be either but as you're a member you could search the archives for it. The value may vary with the length of wire tested. Mark has it right about testing for zero Ohms by shorting the probes together. When you use it don't let you fingers touch the probes. Skin is conductive and will skew the readings.
Luck
Colin 89GT.
Sounds like you're doing it right but your meter may have a fault. (Battery?) The upside-down U with feet is the 'Ohms' character. Symbol for resistance. I don't know what the value should be either but as you're a member you could search the archives for it. The value may vary with the length of wire tested. Mark has it right about testing for zero Ohms by shorting the probes together. When you use it don't let you fingers touch the probes. Skin is conductive and will skew the readings.
Luck
Colin 89GT.
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From: Nova Scotia
The resistance for the plug ends on the 16v cars is 3000 ohms (3k), but may measure higher - the distributor cap end and wire will have <5 ohms, as Porsche specs 'real' wire: the idea is that each lead has an identical resistive load between the cap and the plug. I think the same value applies to the 32v cars, but please check: the same principle applies, in that all leads are of wire with the design resistance built into the plug connector.
You can test this out by removing one of the wires from your 16v car - the plug end if threaded onto the wire: just unscrew it.
You can test this out by removing one of the wires from your 16v car - the plug end if threaded onto the wire: just unscrew it.
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From: Honolulu and sometimes L.A.
Hey Joe
Not sure exactly what the issue is...it sounds like the meter is trying to tell you it is out of range. When making a resistance measurement always touch the two probes ends to each other first. You should get a reading near zero. This will make sure the meter is set up correctly. If you dont get this then try wiggeling the probe connectors around or fiddling with the settings some more. Even electrical engineers get it wrong and need to fiddle sometimes.
If you still dont get a reading you may have blown a fuse. If you have it set in current mode and connect it to battery voltage you will blow the fuse. Pretty easy to do. It should be in or near the battery compartment and most units have a spare in there too.
Basic background....I usually use a water analogy when describing electricity. Imagaine a water hose with a kink. Voltage is like water pressure in the hose. You can have pressure even if the hose is kinked and no water is flowing. Current is like the flow of water in the hose. It will only move if there is pressure there to move it and the kink does not completly shut it off. Resistance is like the kink. A completely closed kink is infinite resistance and no kink at all is zero resistance.
Not sure exactly what the issue is...it sounds like the meter is trying to tell you it is out of range. When making a resistance measurement always touch the two probes ends to each other first. You should get a reading near zero. This will make sure the meter is set up correctly. If you dont get this then try wiggeling the probe connectors around or fiddling with the settings some more. Even electrical engineers get it wrong and need to fiddle sometimes.
If you still dont get a reading you may have blown a fuse. If you have it set in current mode and connect it to battery voltage you will blow the fuse. Pretty easy to do. It should be in or near the battery compartment and most units have a spare in there too.
Basic background....I usually use a water analogy when describing electricity. Imagaine a water hose with a kink. Voltage is like water pressure in the hose. You can have pressure even if the hose is kinked and no water is flowing. Current is like the flow of water in the hose. It will only move if there is pressure there to move it and the kink does not completly shut it off. Resistance is like the kink. A completely closed kink is infinite resistance and no kink at all is zero resistance.
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Joe... be sure battery is good & installed properly.
Sounds like you have a digital unit & it at least turns 'on'.
Does it have a function button - volts ac/dc, ohms, amps, etc?
Also, look at leads & make sure they look continuous
and making contact/connection all along length.
G'luck.
Sounds like you have a digital unit & it at least turns 'on'.
Does it have a function button - volts ac/dc, ohms, amps, etc?
Also, look at leads & make sure they look continuous
and making contact/connection all along length.
G'luck.
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Thanks for the replies. I think there is a problem. Maybe I broke the meter already. (Wouldn't be a first for me) Anyway, when I touch the probes together with the meter set on resistance, nothing happens. I just have the 1 there. The only exception to this if I put meter dial on 200m, then I get a reading that moves around and settles back at the 1. 
If I switch the dial to the Scale for F and set it on 2n, I get a reading of .003 when touching the probes together. 20n gives a reading of 0.00. At 200n the reading is 00.0.
The battery is new, as is the unit. Could it be defective? Or, more likely, operator error? Any thoughts as to cure?
Thanks
If I switch the dial to the Scale for F and set it on 2n, I get a reading of .003 when touching the probes together. 20n gives a reading of 0.00. At 200n the reading is 00.0. The battery is new, as is the unit. Could it be defective? Or, more likely, operator error? Any thoughts as to cure?
Thanks
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From: Mountains of GA!
Joe - you didn't happen to try and measure something on your battery's terminals did you? In the wrong setting on the meter, this could burn up something inside...also - there should be a couple of different places to plug in the leads...make sure they are in the correct receptacles.
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Mark,
I have only tried to measure things on the work bench, nothing with any electricity in it.
There are four possible locations to plug the leads.
a yellow one marked unfused, 20A max,
a white one marked, unfused, mA 200mA max,
a black one marked COM and
a red one marked V/Omega. (Upside down U with feet)
I have had the black lead plugged into the black COM location and the red lead plugged into the place marked V/omega.
If it had a blown fuse, it wouldn't work at all would it? It does show some numbers, as I mentioned earlier, so I assumed the fuse is ok.
Should I take it back or am I doing something wrong?
Thanks
I have only tried to measure things on the work bench, nothing with any electricity in it.
There are four possible locations to plug the leads.
a yellow one marked unfused, 20A max,
a white one marked, unfused, mA 200mA max,
a black one marked COM and
a red one marked V/Omega. (Upside down U with feet)
I have had the black lead plugged into the black COM location and the red lead plugged into the place marked V/omega.
If it had a blown fuse, it wouldn't work at all would it? It does show some numbers, as I mentioned earlier, so I assumed the fuse is ok.
Should I take it back or am I doing something wrong?
Thanks
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From: Portland, Oregon
Originally Posted by macreel
Joe... what make & model is this unit??
I will take it back and exchange for another one, or..... have them show me how to work the one I have.
I warned you guys this topioc might be pathetic.
Sorry.