Page Index Toggle Pages: 1 Send TopicPrint
How to read Porsce wiring diagrams (Read 1864 times)
Global Moderator

Posts: 9370
Joined: Apr 26th, 2005
Gender: Male
How to read Porsce wiring diagrams
Aug 11th, 2013 at 11:57am
Thanks to Chewey we have this

Re: Alternator/Electrical Troubles
« Reply #1 on: Aug 7th, 2013, 9:36am »  Quote  Modify   Remove
Electrical is easy once you understand wiring diagrams.  Highly recommend reading up on how to decipher them.  They seem overwhelming but they are easy to read when you take it wire by wire and bit by bit.
Here's sort of a basic tutorial on Porsche wiring diagrams....
The diagrams will generally go from left to right.  There will be a color code before it starts, usually the page before with sort of an overview of what symbols mean.
From there you have the TOP and BOTTOM of the diagram which represents + and - so anything connecting to the TOP of the diagram is a 12+ wire.  Anything on the bottom, usually brown in color, is a ground.
Now, sometimes a circuit will go up to the top of the diagram and branch off in roman numerals with a number.  For instance... IV15 - The roman numeral is the section of the diagram and the number itself is the track number or circuit number.  
So if on section 1 we see a circuit that says IV5 then we need to go to section 4 and look for circuit 5 and follow it, that is the same circuit that finishes off elsewhere.  Very simple.
In this case, if we use the various wiring diagrams on the internet, we find that the charging circuit starts in section 1 on the bottom left.  It continues UP to the top and goes off to section IV circuit 32.
In section 4, circuit 32, we can see it goes straight to the instrument cluster on a blue wire.
If we look at the gauge cluster in the various wiring diagrams we can see that most of them get power from the cluster from various sources.  Many are "ground switched" circuits, so the other question would be if other bulbs turn on when they should.
For instance, turn signals use the same part of the circuit for grounding as the generator light, do your turn signal arrows light up on the instrument cluster as they should?  If not you may have a grounding issue.
These are just a few ideas and suggestions, but without some probing with a multimeter and more testing, it will be difficult to tell what the issue is.  A quick google search for "944 wiring diagram" should yield you tons of results.  Alternatively, if you have a shop manual or haynes manual, it will be in there (highly recommend getting one).

e mail&& free in the USA 1 866 944 7883&&outside the USA&&1 954 968 3766&&FAX -1 954 968 3798
Back to top
IP Logged
Page Index Toggle Pages: 1
Send TopicPrint
Bookmarks: Digg Facebook Google Google+ Linked in reddit StumbleUpon Twitter Yahoo
  « Board Index ‹ Board  ^Top