wiring basics

[warey]

found this in one of my old text books

1.Set up the meter for a continuity check
Make sure there is no power connected to any circuit that you test for continuity, then prepare the Digital Volt Ohm Meter or DVOM for testing voltage by inserting the black probe lead into the “common” input port, and the red probe lead into the “Volt/Ohms” input port.
2.Check the meter function
Turn the rotary dial of the DVOM to the mode that includes the term “Continuity”. The Digital Display should now give you an ‘Out of Limits’ reading indicating that there is not a continuous circuit connection between the two probes. Touch the probe ends together. The display should now give a zero reading, which indicates no resistance. This means that there is a continuous circuit through the probes. Some meters also indicate continuity with an audible tone.
3.Check a fuse
One typical use of the test is to determine whether a fuse needs to be replaced. If the fuse has been overloaded and ‘blown’, then it will no longer complete a circuit when a DVOM is used to test it. To check this, place the black probe on one end of the fuse and the red probe on the other. If the fuse is functioning correctly then the reading will be zero, indicating a complete, or closed, circuit. If the fuse is open, then there will be no reading and no tone, indicating an incomplete, or open, circuit.
4.Test other components
A continuity test is used to check for a broken circuit caused by a break in a cable or lead, or caused by a component becoming disconnected. The same test can also confirm whether there is continuity between components, which are not supposed to be connected. When this occurs, it is known as a ‘short circuit’. This test can also be used to check circuits that are suspected to have a high resistance

[dehagoris]

thanks alot for your help warey its becoming alot clearer,think ive opened a can of worms but keen to learn more lol

[warey]

no dramas at all i know it may appear that im stuck on mutimeters but learning how to correctly use a meter was a big help to me when i started out and i quickly found if you miss enterpret what it says or dont use one you can spend hours and hours chasing you tail lol, alot of the equipment i work on is used in a very corrosive enviroment so most faults are internal caused by rotten wiring that is virtually impossible to see, with out a meter id be stuffed.
another quick one i learnt was depending on the problem the direction for fault finding changes, sounds simple but its easy to get side tracked and go on different tangents when looking for that ellusive fault, make a plan and stick to it ruleing out problems as you go

[dehagoris]

yeh mate can see how that could be a headache,fortunately my rig is in pretty good knick so with any luck would be fairly straight forward to find any problems with it,will get myself a multimeter before too long.thanks to all whove replied to this thread
greg

[warey]

yeh mate can see how that could be a headache,fortunately my rig is in pretty good knick so with any luck would be fairly straight forward to find any problems with it,will get myself a multimeter before too long.thanks to all whove replied to this thread
greg

you can pick up a reasonably good multimeter from some where like leading edge electrical or dick smith for under 50 bucks. may as well grab a test light while your there, makes testing fuses heaps easier. worth mentioning that just because there is a sharp point on the meter probes and test light that looks good to poke into the insulation of wires because its easier that back probing, dont do it allows crap to get into the copper and can rot out.

[dehagoris]

ah yep thats good to know thats probly the first thing id do because ive seen it done before lol

[DingDuck]

Yendor is quite right in regard to the Tools you will need to check the electrics. I've found a couple of things over the years though.
A Multimeter is good for checking continuity of a circuit or fuse etc. (Ohms scale on the meter), but they can lead you down a blind alley when checking voltage, particularly if they are a Digital meter. Being a high impedance device, I have measured 12v on a open connector, but can't get the circuit to work. This may be because of a high resistance joint. The Test light is the best for this as it introduces a 'load' to the circuit being tested. Can save you hours of chasing your tail. Never assume a fuse is blown only by expecting to see a black mark inside the fuse. Have seem many fuses where the fuse wire will just break off the solder joint on the end cap, especially small current 3AG fuses. All looks good, but.... Thats where the multimeter comes in handy. I'm certainly no expert on auto electric's as they can be tricky sometimes.
Good Luck and Cheers