Can anyone direct me to anyone who has a comprehensive wiring diagram service for the European market??

The only good one I know of is Mitchell which is based in the USA for USA vehicles.

Looking at Autodata over the years has altered my opinion on the wiring diagram side of the data.

I thought is was good & still is if the diagram data is there.

But there seems to be a awful lot of gaping holes where our survey says..... "UH URRRR"
Even for models of vehicle where you would expect it to be there as of right.

I need a source of wiring diagrams A to Z

Peter

"I need a source of wiring diagrams A to Z"

You wont find what you want.
Autodata, HGS, Alldata & E3 will all obtain diagrams which are not included.

Manufacturer site subscriptions are the best bet but even those occasionally fall down.

Steve

Unfortunately this is a political thing. In the USA their thinking is, if they make all of the information available to the aftermarket then owners will buy there cars knowing that any qualified tech will have the information to do repairs,( sort of anti import thing) then there cars will more likely sell.
On the other hand, the European manufacturers want everything back to the dealers to keep there franchisee's happy.

I'm not sure it's political. It's more a case of the sheer complexity and vast range of vehicles that we see in the UK.
It was brought home to me a long time ago when I needed a diagram for a Citroen and I had a friend at a dealership. I was able to borrow what I required. The number of variants and update amendments for just one model filled a fairly thick loose leaf binder.
Repeat that across the entire vehicle parc and you begin to see the difficulty aftermarket suppliers of information are up against.
No one company could realistically supply everything from A to Z.

My feeling is Autodata is not persuing data vigorously enough.

We & the aftermarket pay a lot of money for the information they provide.

They boast on the homepage number of vehicle added & updated but that does not mean the information is comprehensive.

They should focus more on wiring diagrams & component testing & location & waveform repo.

Christ! We get tyre pressure data but look for a firing order & cylinder layout!! NO! SORRY! Straight away finger stuck up arse.

Hi Peter

"My feeling is Autodata is not pursuing data vigorously enough"

I can assure you it's not for the want of trying. I visited Autodata about 8 years ago. All the wiring diagrams have to be bought from the manufacturer, they cannot just scan them from different sources and put them on Autodata as this would be a breach of copyright

When they do get the wiring diagrams they then have to reproduce them in their own format on PC's which can take weeks or months to complete, same goes for Fuse Locations, Timing Belts, Chains etc, this is why sometimes errors in data may occur (human error)

The problem is many manufactures are withholding tech data and wiring diagrams, without access to it Autodata cannot reproduce it, or they may be given it but not aloud to reproduce so you will have to contact them for a copy. They cannot just pop onto a manufactures site for 30 Euros and download it all and stick it on Autodata, they have to negotiate licences

The problem is only going to get worse as electronic systems and wiring becomes more complex. As suggested above, dealer sites are going to be the only route to data. The more the manufacturers charge Autodata to supply data, the more we will have to pay in subscriptions

Autodata will be like some of the diagnostic scanner companies, they will rack it in for as long as they can

Peter

One of the problems with wiring diagrams from any source is being able to interpret how the circuit functions.
With more control units, or for the want of a better expression 'black boxes', diagnosing the problem even with the correct diagram, can be a difficult task.
What's often needed is an explanation to go with the diagram. As a simple example, take the Ford electronic throttle control; I struggled for a while, until I found out Ford use both an analogue and a digital signal from the pedal. Just looking at the diagram doesn't tell you this. If you don't know what to expect, and an output or input is missing, you can't make an accurate diagnosis.

What you are saying Tom is we have to go back to fundemental back probing of units, power & ground checking to find out the circuit design.

Look at recient newish vehicle oxygen sensor voltage readings!!!

Some show between 0.1 of a volt switch, if you can see a switch at all! Due to wideband sensors.

Some show mA readings of which is the only way to detect wideband sensor switching.

I have also noticed that some data PID readings you get on some manufaturers will only show downsteam (no upstream) sensor mA readings & vice versa upstream (no downstream)

The question now is how is the manufacturer interpreting what data readings are required for a engineer to diagnose a fault on oxygen sensor setups.

Some only give voltage
Some only give mA
Some give both
Some give upstream (no downstream)
Some give downstream (no upstream)
Some give both
Some say potato
Some say potaato
When do we call the whole thing a bicycle.

Found a odd one where it appeared to have a data PID completely missing for bank 2 upstream!!!!

Me thinks the manuFATurers are creating confusion for us aftermarket peoples

And don't forget the manufacturers data and diagrams can have errors as well !!

remember a few years ago finding one during a Frank Massey course.