I'm trying to get good sets of wiring diagrams for both a 2002 New Beetle 1.9TDI and a 2003 Forester 2.5x in order to build the engine harness for my WRX TDI project.
Normally, I would go to the public library and use ALLDATA or Mitchell to look up wiring diagrams. This is tedious, since these services don't really want you downloading diagrams, you either have to print and pay per sheet, print each individual sheet to PDF and save to a flash drive, or screenshot everything. Plus, I'm now 30 minutes away from the library, and I honestly don't know if they're letting people sit and use public computers at this point for virus reasons.
I thought I could get away with using Haynes/Chilton paper manuals, but the wiring diagrams in these are bare minimum. I picked up one for the Beetle and while it has a complete wiring schematic, and it could be done, I would be flying blind in a lot of areas. Sure, it says that wire A goes from the ECU to sensor A, but it doesn't list the ECU pinout, or the connector shape or pinout at the sensor end, or the different connectors that the wire might pass through on its way. For items like the AC control or cruise control, the Chilton manual doesn't even bother to say which control wire is which or describe the operation of the switches.
What is my answer for good manuals with good, complete wiring diagrams? I hear the Bentley manual is good for VW, but they're expensive. Is the wiring information more complete with ECU pinout and connector diagrams and pinouts? What is the Bentley equivalent for a Subaru?
Perhaps I should buy the year subscription to ALLDATA DIY? Anyone have experience with this product, or comparison to the professional version of ALLDATA?
Was gonna say a bentley for the vw, yes they have every pin out. A FSM is what I would do for Subaru, but Id bet there is diagrams for free online.
The factory for sure. The Subaru ones are out there, possibly by subscription. I have the factory manuals for a few, but not yours.
They all reprint from OE diagrams.
Beware intepreted diagrams like Alldata will do sometimes. Non OE means someone looked at the OE diagram and made a different one, and sometimes they get things wrong. Got my ass kicked on an O2 sensor diagnosis because of this, all of the terminals on the connector were 90 degrees off.
Here's the Subaru source.
https://techinfo.subaru.com/stis/#/login
You can download PDFs when subscribed, so take the 72 hour access and save what is appropriate.
Keith Tanner said:
Here's the Subaru source.
https://techinfo.subaru.com/stis/#/login
You can download PDFs when subscribed, so take the 72 hour access and save what is appropriate.
Nice, thanks! I think that might be just the ticket for the Subaru end of things.
Too bad there's no online (cheaper) version of the Bentley VW manual, those things are pricey. I might just be able to get away with good diagrams for the host vehicle, since the donor engine wiring really just needs to go from A to B the same way it did in the VW.
Pete. (l33t FS) said:
They all reprint from OE diagrams.
Beware intepreted diagrams like Alldata will do sometimes. Non OE means someone looked at the OE diagram and made a different one, and sometimes they get things wrong. Got my ass kicked on an O2 sensor diagnosis because of this, all of the terminals on the connector were 90 degrees off.
On the other hand, Alldata's interpreted diagrams are a LOT easier to read than OE VW diagrams; the factory VW diagrams are some of the most annoying that I run across on a regular basis.
MadScientistMatt said:
Pete. (l33t FS) said:
They all reprint from OE diagrams.
Beware intepreted diagrams like Alldata will do sometimes. Non OE means someone looked at the OE diagram and made a different one, and sometimes they get things wrong. Got my ass kicked on an O2 sensor diagnosis because of this, all of the terminals on the connector were 90 degrees off.
On the other hand, Alldata's interpreted diagrams are a LOT easier to read than OE VW diagrams; the factory VW diagrams are some of the most annoying that I run across on a regular basis.
Once you "get" track style diagrams, there are advantages. Be nice if they had a legend for every module number and connector on every page.
Volvo is the worst for that. Everything needs a secret decoder page to understand the diagram, NOTHING is labeled except for obscure, non-DIN identification codes.
(99% of the Euro i used to do was VWAG and Volvo, because other shops refused to work on them)
You're right, Volvo diagrams are even worse. I don't see these nearly as often, but they seem to have a mentality behind them with "We don't want to change the diagrams based on what language people will read them in, at all."
MadScientistMatt said:
On the other hand, Alldata's interpreted diagrams are a LOT easier to read than OE VW diagrams; the factory VW diagrams are some of the most annoying that I run across on a regular basis.
Ah yes but once you learn how they work they are so easy to follow and people think you are one of the chosen ones 
X10 on for VW the Bentley being the one to get.
You might be able to find what you need at this link for the Subaru, it looks like there should be the factory service manual for the Forester in there but not sure if it will be exactly what you are looking for. There's lots of other interesting stuff if you start poking around the parent directory etc.
http://jdmfsm.info/Auto/Japan/
