Tachometer wiring

[tikihut]

Need a little help with a tach. 73 911 targa with a 76 2.7 motor. what feed the tach ?

[al lkosmal]

The tach signal is typically a purple/black wire....
You have a 73 targa with 76 engine........73 was the year that the ignition changed to CDI...midyear, so pre-73.5 ignitions would drive the tach from the points signal, like a 72, i believe and post 73.5 changed to the Bosch CDI ignition and the tach drive can be tapped into at the CDI.....

1st pic shows the pre 73.5 ignition with the purple/black tach wire from the points



2nd pic shows the post 73.5 with the purple/black tach wire from the CDI



Also, the tachs changed throughout the years and some of the signals are not compatible ith the tachs and an adaptor may be required....pics below show the differences




regards,
al

[tikihut]

Good info. I'll see what i can do. Thanks Al!