Instrument question speedometer and clock

[Jim911tt]

Hi, I have a 1987 Carrera 3.2 that I recently purchased. Does anyone have an electrical schematic? Also, for a repair manual which one is recommended and why? I just purchased the Haynes manual but if there is a better manual I will purchase that too. Any assistance is appreciated. I am asking for the schematic because on the pelican website it shows the wiring to the speedometer. I have an extra black wire that is in the came harness as the brown or ground wires and is not landed. I am wondering what it is for before I put things back together. Also, my clock does not work and it was just repaired. I know I will have to swim upstream to find out to diagnose why and if anyone has ideas that would be appreciated too.

[Fab64]

Lots of people here (including me) use the Bentley manual:

https://www.amazon.com/Porsche-911-Carrera-Service-Manual/dp/0837616964/ref=asc_df_0837616964/?tag=hyprod-20&linkCode=df0&hvadid=312014160183&hvpos=&hvnetw=g&hvrand=12040009868841946012&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031563&hvtargid=pla-455120391057&psc=1

However, some people say the wiring diagrams in it aren't always accurate.

[Jim911tt]

[thank you

[Schulisco]

The Bentley is good, no question.
I prefer to use the Haynes manual because the circuit diagrams are easier to read and the book is more handy while working at the car:

https://haynes.com/en-us/porsche/911/1965-1989
I keep this book in the car as a reference book.

There are also online resources:
http://www.911c1.de/porsche/Schaltplaene/plaene1-10_carrera_32.pdf
https://classickabelboomcompany.com/wiring-diagram-porsche/

Thomas

[tschall]

A great resource for original manuals is 86 911 Targa. He offered much needed assistance and understanding when I had questions. He has '86 manuals. Few things changed in an '87. I can also offer a pix from my '86, though detail is ...