what is a good voltmeter/ohm meter....
#1
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what is a good voltmeter/ohm meter....
I am not an electrical guy, but need to troubleshoot a no start problem. what is a good voltmeter/ohm meter for my purposes ?
also any guidance/procedure for checking grounds, solenoid and starter would be helpful.
thanks
also any guidance/procedure for checking grounds, solenoid and starter would be helpful.
thanks
Last edited by 92PGC; 01-04-2010 at 11:10 PM.
#4
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Harbor Freight has a digital VOM for $8 (I've bought them on sale for as low as $1.99 ) and they are accurate. I'm an EE and I own two of them, plus some other name brand ones. Its plenty good for car work!
#5
Melting Slicks
I am not a fan of HF, for anything except the few non-Chinese sourced items, like some sanding disks, which are not really any savings. This, because I like the reliability and longevity of quality tools; also those that do not damage what I am working on. I prefer to find great used gear, because it works for me, not against me.
You might search online to learn some electrical troubleshooting lessons and basic circuitry. Most of what you will need for your car is very basic, involving reading voltages and resistance values, like open (blown) fuses, bulbs, broken wires, bad grounds.
Consider, also, getting a 12vdc test light. It has an alligator clip to attach to ground and a sharp pointy probe to check for (in most car cases) 12vdc.
#7
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The question is what are you trying to do? If all you want is basic continuity and 0-20 volt DC readings any inexpensive analog or digital multimeter will do the job. The $3.00 or less Harbor Freight digital multimeters are adequate for probably 95% of automotive troubleshooting.
Better meters will typically have less loading of circuits under test; this can be critical with certain electronic circuits if a high accuracy measurement is desired. Higher resolution displays, either bigger analog meter movements or more display digits, are available on higher dollar meters. I find a temperature input (thermocouple input) to be handy for some tests. Fluke, Simpson, and BK Precision are among the names for high quality multimeters. Be aware that may spend well in excess of $100.00 for one of their meters but they will last you a lifetime.
While digital meters are more typical anymore, analog meters can be easier to use if troubleshooting an intermittent. The least significant digits "jumping" of a digital display can be confused as intermittent operation. Movement of the analog needle is easier to detect if troubleshooting an intermittent circuit. Some better digital meters have a bargraph display in addition to the digital display to be more "analog like" in their operation. Peak hold is another feature of better digital meters that can be helpful.
I own both Fluke, Simpson, and cheapie meters. I keep the cheap meters in my toolbox for quick troubleshooting and use the Fluke or Simpson where their capabilities are desired.
Keep in mind that most hand held multimeters are limited to a maximum of 10 amps for current measurement. Many circuits will exceed the 10 amp limit if you are trying to measure current. Do look for a mutimeter that has a fuse on its current measurement circuits. I would buy an external shunt for high current measurements or an instrument dedicated for high current measurements if you have that need.
Steve
Better meters will typically have less loading of circuits under test; this can be critical with certain electronic circuits if a high accuracy measurement is desired. Higher resolution displays, either bigger analog meter movements or more display digits, are available on higher dollar meters. I find a temperature input (thermocouple input) to be handy for some tests. Fluke, Simpson, and BK Precision are among the names for high quality multimeters. Be aware that may spend well in excess of $100.00 for one of their meters but they will last you a lifetime.
While digital meters are more typical anymore, analog meters can be easier to use if troubleshooting an intermittent. The least significant digits "jumping" of a digital display can be confused as intermittent operation. Movement of the analog needle is easier to detect if troubleshooting an intermittent circuit. Some better digital meters have a bargraph display in addition to the digital display to be more "analog like" in their operation. Peak hold is another feature of better digital meters that can be helpful.
I own both Fluke, Simpson, and cheapie meters. I keep the cheap meters in my toolbox for quick troubleshooting and use the Fluke or Simpson where their capabilities are desired.
Keep in mind that most hand held multimeters are limited to a maximum of 10 amps for current measurement. Many circuits will exceed the 10 amp limit if you are trying to measure current. Do look for a mutimeter that has a fuse on its current measurement circuits. I would buy an external shunt for high current measurements or an instrument dedicated for high current measurements if you have that need.
Steve
Last edited by azrocketman; 01-05-2010 at 11:15 AM.
#8
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Watch the battery voltage while trying to start the car. Normal operation will cause the battery voltage to drop to approximately 9 to 10 volts during starting. If the battery voltage drops and the engine is turning normally then it's probably not a battery, starter wiring, or starter problem. Slow engine rotation during starting or voltages less than 9 volts indicate a weak battery.
If the battery voltage drops to approximately 9 to 10 volts (or less) and the engine does not turn then something may be locking the engine (one remote possibility is hydraulic lock) or something mechanical in the starter/solenoid assembly.
If the battery voltage does not drop to approximately 9 to 10 volts during starting then it's possibly the battery connections, grounds, wiring, solenoid, or starter motor. I'd start by inspection of the battery connections and wiring. There are voltage/resistance measurements you can make but I'd start with inspection first. Write back if you need to know what and where to measure.
A word of caution while troubleshooting. The battery can deliver a lot of current. When measuring and inspecting electrical connections remove any jewelery, especially rings. An extremely painful demonstration of resistance welding will be yours if you are not careful.
Steve
#9
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junk worth what it cost
three items from hf that every vette owner should own (and have basic idea of use): hf 'fuel pressure tester' (<$20) and two of their 'low buck' DVOMs (toss one in toolbox and other in glovebox)
#12
Drifting
Wal Mart has a DVOM with a 10 megohm input impedance that will not load damage sensitive circuits for about 15 bucks. It also has a handy battery checker that loads the battery down to check it. (small dry cell batteries). Great meter with no worries.
#13
Here is one I recommend to those who do not have a good electronic background. It is a little more than those from HF, but it has 10 megohm impedance to protect computer circuits and the auto ranging feature will save a lot of head scratching while you are learning.
http://www.amazon.com/Equus-3320-Aut.../dp/B000EVYGZA
http://www.amazon.com/Equus-3320-Aut.../dp/B000EVYGZA
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Steve
#20
Drifting
Here is one I recommend to those who do not have a good electronic background. It is a little more than those from HF, but it has 10 megohm impedance to protect computer circuits and the auto ranging feature will save a lot of head scratching while you are learning.
http://www.amazon.com/Equus-3320-Aut.../dp/B000EVYGZA
http://www.amazon.com/Equus-3320-Aut.../dp/B000EVYGZA