88 GT Terminator X tachometer wiring help needed

[DeathProof88]

Hi guys, happy 4th of July! So, I'm installing my Terminator X. I have the coolant and oil guages pretty figured out but tracing back my tachometer wiring, I find that it splits off a few ways and doesn't go back to the c110 connector as most videos I've seen do. There's also a resistor in the circuit. Can someone please clarify for me how to wire up the tachometer and coil to the Terminator a little better? I'm overthinking it all possibly...

 

[TOOLOW91]

You are overthinking it bud . It goes right through that connector to the dash . You can wire it right to there I have done it multiple times no issue

The wires at the coil - the red with green tracer can go right back to the grey connector there you have in your hand to plug in the fire wall to get key on .

If you aren’t running a msd box cut the green wire with the yellow tracer on both ends so you can join them in the middle, then tbe white from the tfi harness Holley Holley supplies can run to the green with yellow tracer and terminate them together . The tach will now work along with ignition firing . You’re not using the loose white wire loose in the main harness from the Holley . This is the white wire from the tfi harness

If you’re using a 6 al the white tfi harness runs to the points in on the msd box then the msd out feed the coil

 

[DeathProof88]

Are you using a relay on the red/green wire to trigger a relay as per the instructions? It says to use full battery power to the coil with 12g wire.. also, can I go ahead and remove the rest of the wires in the connectors now? I do plan on getting the a/c to work again in the future.

As far as I can tell I only need the red/green and green/yellow in the Grey connector. And in the black connector, the red/white and white/red for oil pressure and coolant temp.

One more question- does the white wire from the tfi harness just splice anywhere I like into the green/yellow? Or should I terminate it as close as possible to the coil connector?

Here are 2 pictures of my remaining wires.

 

[TOOLOW91]

Are you using a relay on the red/green wire to trigger a relay as per the instructions? It says to use full battery power to the coil with 12g wire.. also, can I go ahead and remove the rest of the wires in the connectors now? I do plan on getting the a/c to work again in the future.

As far as I can tell I only need the red/green and green/yellow in the Grey connector. And in the black connector, the red/white and white/red for oil pressure and coolant temp.

One more question- does the white wire from the tfi harness just splice anywhere I like into the green/yellow? Or should I terminate it as close as possible to the coil connector?

Here are 2 pictures of my remaining wires.

Remember , that red and green tracer wire already powered the coil to begin with factory. I’ve never added a relay for that just used the factory wiring and never had an issue.

Fuel pump I always run the Holley out to the factory relay or a leash depending on the car

White tfi wire can go anywhere in the middle of that green with yellow for the tach and the coil negative. All it is - is the negative pulse

The trigger for the AC on an 88 is in one of those plugs let me look so you don’t cut it and loose that - should be the green with the black stripe

 

[DeathProof88]

Thank you very much! I was going to run the green fuel pump wire under the center console straight to the fuel pump wire on the relay. However there are 2 pink wires, one I'm pretty certain is an old signal to the ecm and the other is the pump. I'd like to remove the unused pink wire from the circuit so I'm not powering a wire for no reason.

 

[TOOLOW91]

Thank you very much! I was going to run the green fuel pump wire under the center console straight to the fuel pump wire on the relay. However there are 2 pink wires, one I'm pretty certain is an old signal to the ecm and the other is the pump. I'd like to remove the unused pink wire from the circuit so I'm not powering a wire for no reason.

Cut and Ground the tan/lt green wire coming out of the relay

Cut and Connect the Holley green trigger wire to the red/black tracer wire at the relay .

The Holley will now control the factory relay circuit as if it were the factory ecu

 

[DeathProof88]

Ok will do!