Intermittent starting issues 75 911.. now non starting

[Brantleycoker]

So I’ve been trying to track down my starting issues for about a month now and am getting a little discouraged. New starter, new battery, and I’m still having problems with the starter engaging. The power at the starter main post is 12.9 v and the yellow wire from the ignition switch reads 8.5 volts. I have the weird seat belt switch in my car also. Any insight would be super helpful… I’m running out of ideas.

[jimtweet]

Try removing relay and jumping the yellow ignition wires. I just removed that box completely from my 75 and connected the yellow wires

[Schulisco]

For a successful CIS troubleshoot first and foremost good knowledge is key! Grab a beer, sit down and relax while watching the complete series of Kurt from KlassikATS about the 2.7 911:
https://youtube.com/playlist?list=PLkWFofpgz2OgF9FdliKnlzuY0pygqRkMj

After that you've a first impression and a pragmatic approach on how to narrow down your issue. On a CIS it's almost never only a single issues due to lack of maintenance for decades...

Thomas

[mysocal911]

So it's a no-crank and not a no-start, right?