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gday crew,
im fairly new to electrical systems in vehicles and was wonderring if anyone knows any good sites or could give a basic run down on how the wiring in cars works,trying to get my head around them so i might have some chance of diagnosing
problems if they occur,seems to be some variations from what ive read so any info would really help
Once you crack the 25 posts mate, you can get the manual .... that said, always good to have someone or somewhere that lays it out in simple English, so would be interested to know of something like this also.Quote:
Originally Posted by dehagoris
yeh mate im no scholar so need someone to spell it out in black and white lol,lookin to install a headlights on feature.but a general run down would help alot in the future for sure
Big Fletch or Yendor would be the best to answer this.
Tony
G'day mate..
Wiring can be a tricky bugga sometimes.. I will try and give you the best easiest run down i can
Essential tools for testing Wiring circuits
-Multimeter
-Test Light
-Wire
-Elec Terminals
-Wire Strippers
Always check fuses first, as they are the weakest point in any wiring system as they are designed to be. most vehicles have 2 Fuse boxes, 1 inside vehicle and 1 in engine bay.
Having a repair manual with all of the vehicle specific wiring diagrams will be a major help and will save you alot of time working out systems. You should never test computer wiring with a test light as this can cause damage to the computer. Only ever use a multimeter (or an LED Test light).
An Altenator will charge at between 13.2v and 14.4v, check the charge rate at the battery and at the back of the Altenator if able to.
Everything in a vehicle must have a power and earth to operate so if something isn't working its generally lost one of these things, its your job to find out which one..
Is there anything specific your after of just abit of a general idea?
Fletcha
are you after basics as in setting a multimeter how to check for shorts, opens and excessive resistance or a bit more indepth? the easiest way i can see is if you can be a bit more specific on what info you are after
sorry fletch pretty well doubled up your last bit. when i started to reply your post wasnt there but the dog went nuts so had to go investigate then when i did eventually submit yours was there oops!
ahaha nah your right mate, happens alot on this forum lol.. The more input and advice the betterQuote:
Originally Posted by warey
I am with Fletch check ALL fuses first.
When fault finding most people will over look the earth side.
Also when chasing a problem where the fuse keeps blowing, I always start with any wiring or electrical items that may have been added to the vehicle such as radios extra lights.
You will be surprised how many times a trailer plug has caused problems with tail lights, stop lights or indicators.
If the vehicle has panel damage have a look around that area for damaged wires.
Bad connections will give off heat, depending on what circuit this is in you may be able to feel the heat with your hand (sometimes even smell the connector melting).
I have always found it best to step back and find out exactly what the complaint is or whats not working, before jumping in and pulling things apart, chances are you will disturb the problem and then it will start working again and you are left scratching your head.
thanks fellas that gives me a good idea where to start,was just after a rough guide to electrics/fault finding as im goin to be doin a fair bit of travelling over the next year or so....cheers
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
thanks alot for your help warey its becoming alot clearer,think ive opened a can of worms but keen to learn more lol
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
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.Quote:
Originally Posted by dehagoris
ah yep thats good to know thats probly the first thing id do because ive seen it done before lol
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