74 914 main wire harness modification, for running a 3.0-6 Options

[Luke M]

I have my brothers main wire harness laid out here on a table. The rear light portion needs some TLC. While I'm at it wanted to delete the under the seat relay. I know just jump the yellow wire and go. I want to clean up that whole mess of wires if possible. My question is what can be deleted and what can't? I plan on adding a few wires for the 3.0 press/temp gauge and maybe a few other spares from the engine up to the gauge cluster.

Maybe Jeff B will chime in here.... @JeffBowlsby

[JeffBowlsby]

My advice would be to don't bother with the deletions. Study the schematic for the circuits you want to delete and you will see that there is alot that is interconnected, which will then require additional repairs. And for what benefit...saving a couple pounds of wire? Also, whatever you renegineer you wil need an EE to figure things out going forward if ther are problems becasue the harness will have no accurate schematic.

[ClayPerrine]

My advice would be to don't bother with the deletions. Study the schematic for the circuits you want to delete and you will see that there is alot that is interconnected, which will then require additional repairs. And for what benefit...saving a couple pounds of wire? Also, whatever you renegineer you wil need an EE to figure things out going forward if ther are problems becasue the harness will have no accurate schematic.

You are describing the harness in my big six. I started with the 73 harness. Then I removed unneeded circuits, re-pinned the relay board connection to work with a /6 relay board, changed the ignition switch, and turn signal switches for the six column, added 14 pin connectors to make the instruments removable without disconnecting all the wiring. I also added two circuits to provide power to the headlights so I could add relays up front.

And I never drew a wiring diagram. I need to do that one day....


Clay