MSD Tech Support Forums

Go Back   MSD Tech Support Forums > MSD Ignition Forums > Installation Questions

Installation Questions Wiring and Tech Information

Thread Tools
Old 10-01-2012, 10:56 AM
Posts: n/a
Default Grey wire on msd 6al

Hello. I have a 83 porsche sc
All the diagrams are great though there is no mention of where the grey wire off the msd harness goes.
I suspect it is the tach output wire.
Is that right?
If so would it connect to the car's harness at TD?

Reply With Quote
Old 10-01-2012, 01:49 PM
msdtech1955's Avatar
msdtech1955 msdtech1955 is offline
Senior Member
Join Date: Jan 2008
Posts: 10,288

from page 2:

The MSD Ignition features a Gray Tach Output wire that provides a trigger signal for tachometers, a
shift light or other add-on rpm activated devices. The Tach Output wire produces a 12 volt square
wave signal with a 22.5 duty cycle.
Some vehicles with factory tachometers may require a Tach Adapter to operate with the MSD. For
more information on Tachometers and MSD Tach Adapters, see the Tachometer Section on page 6.
If your GM vehicle has an in-line filter it may cause the tach to drop to zero on acceleration. If this
occurs, bypass the filter.


Tach output wire. Connects to the tachometer trigger wire or other
rpm activated device.
Reply With Quote


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -6. The time now is 02:04 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
2016 MSD Performance