Hp-j

What’s up everyone, thanks for looking and big thanks for any wisdom, I’m having an issue understanding or figuring out how I’m going to do the wiring in my 86’ mustang, it’s an original 2.3L carbureted car, i already have an ls1 and stand-alone harness and ecu, the issue I’m having is the engine harness original to my car is tied into the headlights horn wiper fluid ect, the harness plugs into the ecu in normal location passenger kick panel, then goes through the fire wall runs to the engine and to the rad support accross the rad support to driver side and back up and through the fire wall and plugs into the fuse box under the dash, it’s very strange to me, anyways I want to eliminate the wires that were for the original engine, and if possible eliminate the original 86 ecu so I can put the new ecu in its place, if I can’t get rid of the original ecu be it because of ac functions or something else I want to keep, then I’d have to get creative with placement of the ls1 ecu, again I really appreciate any help, I’m not a genius, this is my first serious conversion/restoration, so please excuse me for not knowing it all yet, the goal is pretty much an original showroom condition 86’ mustang coupe with an ls1/t56, pretty much all stock in a sense, and then go modding it from there! Again I appreciate any and all wisdom guys!!!

G Atsma

I don't think those cars used an ECU, which means Engine Control Unit. I think you just need to thin the engine wiring out of the harness so all the other functions still work.

Hp-j

Thanks for the reply, oddly enough the car does have an ecu, I have the entire car stripped down to nothing but literally what it needs to roll around, ecu harness dash everything is removed, the idea at first was to just thin it out like you say, but then I came accross the ecu, so I’m not exactly sure what to do with it

Project GatTagO

iTrader: (7)

You may want to track down the original car FSM with all of the wiring diagrams.

Andrew

G Atsma

How big is the box? Like about 4"x 5" x 1" thick? See where all the engine related wires hook up to. There just wasn't that much going on with a carbed engine in '86.

Hp-j

Looks just like a efi Fox ecu harness plugs into it with a 10mm and all

Hp-j

Still trying to figure this out, anyone?

MrHorsepowerLSx

iTrader: (4)

I have an 88 coupe that was OE 5.0/5speed that I'm doing an LS swap on. I removed all the wiring but the power feeds and light power feed wiring. They were located on the fender mounted solenoid. The group of 4-5 wires is what powers the items inside the car like the ignition switch,fuse panel,blower etc. There is a small 14-12 awg wire with what looks like a small metal breaker attached to the end of it, that wire powers the lights to switch IIRC.

Michael Yount

iTrader: (1)

Pretty sure the 86 2.3L was throttle body injected -- has an ecu, but does NOT have a carb. I have a fair amount of experience with the 5.0L V8's from similar years swapped into another car. Mine came out of a Mustang. The engine wiring harness was completely separate from the Mustang chassis harness.