| Author |
Message |
    
Bob Reynolds
Experienced User
Username: bobreynolds
Post Number: 15
Registered: 8-2012
| | Posted on Sunday, 16 September, 2012 - 19:51: |    |
When trying to trace out wiring faults you often have to identify the purpose of a wire purely by its colours. But it can take forever to find a particular wire on the circuit diagram by colour alone. You can be staring at the diagram for hours and hours, and still not find it!
I am wondering if there is a wiring colour reference table somewhere, whereby you can look up the colour(s) of a wire and instantly find its purpose and location on the circuit diagram.
I know that there is a loose standard for wiring colours in British cars, but I have only found it to be of limited use. What is needed is a specific colour reference table for Rolls Royce cars, so that you can instantly find the purpose of a wire by its colour. This would save hours and hours of searching on the diagram with a magnifying glass!
Does such a reference exist? |
Hubert Kelly
Experienced User
Username: h_kelly
Post Number: 39
Registered: 3-2012
| | Posted on Monday, 17 September, 2012 - 02:58: | |
Bob, it has always taken me hours to figure out the wiring situation in a car, and indeed my '68 shadow. If I want to trace a wire which is proving difficult,I disconnect the battery , using a long wire, I connect one end to the positive terminal of battery (which has been disconnected from car) and the other end to the wire I wish to trace. What this does for me, it reduces the number of positive wires to check, to one(one sole wire with positive charge). In other words, I can trace this wire with my 12 volt lamp etc, to see where wire travels to etc thus eliminating one wire at a time. Its the only way I can make logic of the problem , granted it can take hours. Someone might explain an easier way, but to be honest, it would go over my head.
Hk |
Paul Yorke
Grand Master
Username: paul_yorke
Post Number: 859
Registered: 6-2006
| | Posted on Monday, 17 September, 2012 - 04:47: | |
your project for today is . . . |
Bob Reynolds
Experienced User
Username: bobreynolds
Post Number: 17
Registered: 8-2012
| | Posted on Monday, 17 September, 2012 - 06:08: | |
I hope you've got a fuse in your test wire!
It can be dangerous connecting 12v to an unknown wire. It might have an Earth on it. |
Hubert Kelly
Experienced User
Username: h_kelly
Post Number: 40
Registered: 3-2012
| | Posted on Monday, 17 September, 2012 - 06:17: | |
True Bob, you right.. the above post is what I have done, I by no means recommend anyone else, to try same.
HK |
Paul Yorke
Grand Master
Username: paul_yorke
Post Number: 860
Registered: 6-2006
| | Posted on Monday, 17 September, 2012 - 06:50: | |
As a guide (as long as things have not been messed about too much) the theoretical wiring diagram is helpful. Find the component and follow it through the looms and various plugs on it's travels on paper then with a tester on the car.
If you are doing it from the site PDF, print them out at 200% and tape them together.
If a fault can't be fixed and you have to modify something, Write a note and tape it to the component for the next person to find ( or you in a few years!)
Good luck with all that spaghetti! |
Jeffrey McCarthy
Grand Master
Username: jefmac2003
Post Number: 344
Registered: 5-2007
| | Posted on Monday, 17 September, 2012 - 12:19: | |
Good advice re the labelling Paul - I wish it had been followed years ago when somebody modified my headlight circuit to by-pass the safety cutout relay - it would have saved me weeks of mental (and physical) pain!
I'm currently installing a remote for the central locking and have photocopied the instructions & diagrams to tuck into a little plastic bag near the unit for future reference, ditto the relevant pages from the new stereo head unit handbook. RT's diagram for the window mod is taped to the front passenger door.
Confusing bits of wire can also be labelled - it's amazing what you can forget in a week of playing with the pasta.
The green plastic wires from fuse 11 for example go to the air-con, the warning lights and buzzer, the gauges and also to the height control unit. Once each is identified label it - it is so easy to get the connections backward when you're tired. |
Jeffrey McCarthy
Grand Master
Username: jefmac2003
Post Number: 345
Registered: 5-2007
| | Posted on Monday, 17 September, 2012 - 19:16: | |
Also to add in defence of the practical wiring diagrams.
These are even more of an eyestrain to read and to learn.
Their real beauty comes into its own when you need to check the toeboard (and probably other) plugs. Be aware that the ones available end around car 9000.
Each plug has a clear plastic blanking insert to block a missing male pin on the connector plate -this makes it easier to figure out which order the plugs are re-inserted.
Sometimes the female connectors have been inserted into the wrong opening - or more commonly- aren't sitting properly leading to 'intermittent' hours of fun.
A liberal spray of electrical grease on the plugs and the mounts makes re-connecting easier.
Always, on each plug, use your finger to check that each lucar connection has mated.
By way of explanation, and expiation perhaps, on both occasions that my car has needed to be trucked to points north during the last 5 years it has been in the middle of what can only be described as amateur electrical disarray: there's an auto-electrician in the southern highlands to whom I owe at least one full case of hard liquor! |
Bob Reynolds
Experienced User
Username: bobreynolds
Post Number: 19
Registered: 8-2012
| | Posted on Tuesday, 18 September, 2012 - 13:43: | |
I might make up a wiring colour reference table.
It might take a few days, but will save hours of frustration in the long run. |
Bob Reynolds
Experienced User
Username: bobreynolds
Post Number: 34
Registered: 8-2012
| | Posted on Thursday, 21 February, 2013 - 01:18: | |
Well, I did make up a Wiring Colour Reference Table and it has already saved me countless hours of frustration in trying to trace various wires and faults.
The table consists of 2 parts:
Part 1 lists all the equipment in alphabetical order and the colours of the wires. This is no more than what can be found from the wiring diagram, except that it is quicker to find.
Part 2 is a reverse look-up table and the most useful one. It can be used to identify the purpose of any wire on the car just by its colour. All the wiring colours are listed in alphabetical order, and the table shows where each one is connected to.
The information was compiled from wiring diagram TSD 4028 which covers the 1974/75 Silver Shadow, and possibly earlier and later models for all I know. In any case, the differences should mostly be minor ones.
The attached tables are in a simple txt file which can be read by any word processor. I hope members find these tables useful. Even though great care was taken, there will be errors. The original diagram was unclear in 1 or 2 places. Please let me know of any errors found.
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Geoff Wootton
Frequent User
Username: dounraey
Post Number: 85
Registered: 5-2012
| | Posted on Thursday, 21 February, 2013 - 03:15: | |
Many thanks for that Bob.
Seeing all the parts listed in this way also adds structure to the electrical system - makes it less daunting than looking at all that spaghetti in the wiring diagram. |
Bob Reynolds
Experienced User
Username: bobreynolds
Post Number: 35
Registered: 8-2012
| | Posted on Thursday, 21 February, 2013 - 03:16: | |
Oh, and the tables can also be used to identify unknown relays. If you want to know what a particular relay does, just look at the colour of one of the wires. Look up that wire in table 2 and it will tell you what the relay is.
As a check, find the relay in table 1 (all the relays are listed together under 'R') and this will confirm the colours of all the other wires on the relay.
The same with other 'mystery' components that you can't identify, like the various heater valves and actuators, etc! |
Geoff Wootton
Grand Master
Username: dounraey
Post Number: 1234
Registered: 5-2012
| | Posted on Friday, 13 May, 2016 - 03:57: | |
Phew - I had trouble finding this thread. I'd lost my local copy of the wiring colours table compiled by Bob Reynolds, but thankfully it is still here.
I came across a disconnected slate/green wire behind the dash. A quick check of the table tells me it is part of the radio balance circuit, no longer used on my car. A previous owner must have just left it there when s/he replaced the radio.
It's a really useful table and worth taking a copy.
Geoff |
Brian Vogel
Grand Master
Username: guyslp
Post Number: 1901
Registered: 6-2009
| | Posted on Friday, 13 May, 2016 - 04:54: | |
Geoff,
It's definitely very useful and I snagged a copy back when it was originally posted.
I also have the following and, unfortunately, have no record of its author. This is odd because the creation date is within the year and I usually note that when I save a piece of information. I don't want to be taking credit for someone else's work.
What's interesting is the inclusion of information of what wire colors tend to get used for what purposes. Now that I've had some time digging around I know that a number of things, e.g., black for ground/earth, brown for primary battery power, are true (or at least largely true).
Brian
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Geoff Wootton
Grand Master
Username: dounraey
Post Number: 1235
Registered: 5-2012
| | Posted on Friday, 13 May, 2016 - 05:28: | |
Thanks Brian |
Bob Reynolds
Grand Master
Username: bobreynolds
Post Number: 390
Registered: 8-2012
| | Posted on Friday, 13 May, 2016 - 05:49: | |
Thank you for finding my wiring colour chart.
Even I didn't know where it was! |
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Wiring Colours
Wiring Colors & Connectors