[David Claflin]

In an attempt to make his mustang as light as possible a buddy of mine is thinking of removing as much wiring as possible from his EEC-IV harness and still retain functionality of the EFI system. I've got a chip in it, so the TAB/TAD, and EGR are turned off, so those wires could be pulled. I was thinking the fuel pump relay and fuel pump cut off at the back of the car could be moved closer to the EEC processor to shorten the length of the wiring. What else do you think could be eliminated and not create driveability issues?

[cgrey8]

The motivation here is intriguing and confusing at the same time.

This person is interested in shaving weight so badly that they are seriously looking to reduce a few ounces of copper and plastic, but they are still using an EEC-IV to control the engine which is likely of the same era? Is this just some kind of personal challenge or are there real stakes involved with this motivation? I'm just thinking there has to be far more productive places to look to reduce weight (and drag) than snipping a few wires out of the vehicle. For instance, aluminum heads/block, removal of sheet metal parts, replacing steel suspension components for aluminum ones, etc etc.

But as to the actual question, I guess if you just really wanted to reduce wire length, you could get crazy and relocate the EEC up closer to the engine and shorten every wire in the loom. You would need to build some kind of water-resistant enclosure for the EEC to mount in. Many EEC-V trucks like mid 90s era Rangers and Explorers located the EEC in the top of the firewall, directly above the engine which makes for a pretty short wiring harness as compared to the Fox body looms. Here's an example:


Another HUGE weight cutting option would be to ditch the lead-acid battery for a lithium battery. Lithium batteries are so power-sense you can fit the cranking amps of a 20lb battery into something you can hold with 1 hand without straining. That alone would get you FAR FAR more weight-loss than you could possibly get trying to cut copper from the vehicle.

[Mustang_Mike]

Sounds to me like he wants to simplify it to reduce risks of things going wrong and the ease of tracing down wiring issues most likely like getting rid of the salt n pepper shakers if his car has them as theyre quite pesky.....

Like stated its pretty ambitious just to do it for the savings of weight.....

My problem was just the opposite...I needed extra length for my project as the harness wasnt installed in a Mustang and wanted to run the wires from the frame up and hidden behind the engine brought forwards but some things your buddy sholdnt shorten are the grounding wires on pins 40 and 60 and dont meld in any grounds to them either.........

In the harness below youll notice by the factory coil and attached off of the branchff is wiring for my MSD 6 box but still have the factor coil attached and thats because the wire the coil is attached to gets tucked away and if the MSD burns out all I have to do is pull the plug off the MSD box and swap the coil output wires and Ill still get home on the stock trigger pulse..



Good Luck