Help Reading German Schematics

[lucittm]

Can someone help me here? I am trying to decipher the square boxes on the Porsche schematics. I cannot find a reference in the manual. Some of the squares have numbers in them and some don't. What do the numbers refer to? There are duplicates on some of the pages. And, they are repeated on different pages. I thought they could be plugs/jacks but the numbers do not correspond to the "T" code in the back of the schematic (those plug numbers are not in an outlined box).
They are shown in red below.

I know the rectangular boxes show a reference point that is off the page. Those are shown in blue below. I figured that one out on my own.

Thanks,
Mark

[Gunter]

If you follow the path of BR (Braun = Brown), it looks like it leads to ground.
1.5 must be the wire-size.

[lucittm]

Dr. Gunter,
I agree with your analysis of the wire labeling, and in fact that is a 1.5mm brown wire that leads to a grounding point behind the instruments on the left side.

But, pray tell, what is the significance of the large numeral "1" inside the square? And why is there not a corresponding number inside the square in the red circle on the right, where there is also a 1.5mm brown wire?

These are prominent designations, certainly they have meaning.

Thanks,
Mark

[rsrmike]

The (1) simply means it's ground point #1 The other square is simply a junction point that is not grounded in that particular place.

The D26 in that little square signifies where in the diagram that lead goes, meaning field D, line 26. If you take note of the letter and number that one is in, and then look at D26 on another page, you should see the mental note of where you started from...

Edit, just noticed you knew that last part, sorry

[rsrmike]

You should see a page with all the ground points identified as well as a grid of the car to help you locate them, hope this helps

These diagrams still drive me crazy sometimes, and they continue to evolve, just when you figure out what they mean, they change to some other format. They don't even print diagrams for the new cars, they are all loaded on the Porsche system testers from what I've been told...

[lucittm]

Mike,
The numbers in the box do not consistently reference the ground points in the model year 1991 schematics, that is why I am confused.

In the example I showed, it just so happens that those two circuits are grounded. The one on the left at "Ground Point XV" and the one on the right at "Ground Point (MP) VI".

There are many examples with circuits connected by the squares (with and without numbers) that are connected to sensors and other "live" circuits.

Thanks,
Mark