How to add aftermarket Tachometer to 2003-2004 Navigator?

[94bonestocker]

I've tried the search function, I've tried the Google machine, no luck with how to wire a tach adapter for use with an aftermarket tachometer.

I have a 2003 5.4 4V in my 1960 F100. Im trying to wire an aftermarket tach to monitor revs. I have the MSD Tach Adapter PN 9117 but the instructions say to wire it inline with the main power that feeds all of the COPS. The problem is there is no "Master" wire that controls all of the COPS. They are controlled individually by the ECU.

Has anyone wired an aftermarket tach and if so, whats the PN and any advice. TIA!

 

[driller]

The problem is there is no "Master" wire that controls all of the COPS. They are controlled individually by the ECU.

I've modified a few early 4V Fords over the years. I do not know the specifics of the '03 4V ignition, but generally the Ford ECU controls the grounding of the COP. The power wire is usually red and common to all the COPs.

Looking at the 9117 instructions you want to find this red 12V+ circuit going to the COPs, cut and splice the Tach Adapter inline accordingly. The red 12V+ from the ignition going to the red from the 9117 and then the red/green from the 9117 to the red wire going to the COPs. The gray wire then goes to the tach and of course the black wire goes to a good ground.

I've used the MSD 8913 before to drive the tach, it's very similar.