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First ''milspec'' ECU wiring loom

EFI Wiring Fundamentals

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Hello everyone!

As stated on the title this is my first wiring loom using concentric twisting and tefzel wire etc.

I have done some wiring looms before, as an example for my brothers r33 gts-t skyline. Which was done by using the original loom, now later as I joined the hpacademy I have learned a lot! I got interested when I saw all the beautiful harnesses built by pros and said HEY! why wouldnt I take my part on this. Started to do a lot research in constructing and planning the harness. The engine that this loom will be built is my 1jz-gte. Ecu is a Haltech platinum sport 2000.

When I first started to plan the loom I wanted to use one circular MIL-spec connector for the firewall. Since I am just a poor student I decided that I wouldn't use one. Did this the expensive and easy way and ordered all the separate wires with different colors(M22759/16 Tefzel Wire). Added a bunch of DR-25, ATUM and SCL heat shrink tubing and some needed connectors(Plugs and pins for the ps2000, haltech fuse box etc.) All the wires, heat shrink and supplies came through ProwireUSA.

I got some Engineering PAD-11 from japan, and found set of 2 used Stripmaster wire strippers with L-5560 blades for cheap.

Wire sizes were 18-22AWG used 22awg for sensors etc. and 2core shielded tefzel wire for the OEM cam and crank sensors.

Used the shielded wires as a core for the 1st. layer.

First layer included 8wires which were 18awg ground and power wires, these I found out harder to twist than the thinner 22awg.

2nd. layer had 14wires, couple 20awg and the rest 22awg.

3rd. was totally the fun part lol. 20wires in 22awg, these started to tangle in to each other and in this part I lost my nerves couple of times. Took a cop of coffee and calmed myself.

4th. layer had only 13wires, since there were only 57wires in total.

After each run I made sure that were no overrunning wires.

I also hand layed the fusebox wires, which was a PITA. I secured the runs with kevlar lacing cord. I made one meter(approx. 3.3 Feet) Run for the main loom, and from there the wires will split in to their locations. This one meter should be enough to get the transition under the intake manifold. I will be adding some DTM-connectors to the fusebox and other locations so that the loom should be easily disconnected if needed.

Critique, tips and advices are welcome since this is my first one. I would like to learn a lot more constructing wiring looms and electronics. At the moment I am studying at University of applied sciences and will specialize in automotive engineering and specially ECU and wiring related.

This is the current state of the wiring loom, and will soon add some DR-25 to the main run. Will finish it as soon as I get my engine in to my car again. Bundle size from the thickest point without heat shrink was 16mm. Was pretty impressed by this and how flexible the loom came.

Regards Kalle

wow thats some nice looking loom. I'm miles away from feeling confident enought to do this. Just out of interest does the ecu support all road legal aspects of the car or is it a race spec. For me building a loom to suit a set of parameters for purely my own gains may be possible - but to incorporate all of the other things an oem harness would might take a bit more brain crunching. Well done you.

Martin Uk

Nice work - Looking good. Once you get your head around the technique of concentric twisting, it's not particularly difficult. It does however require you to really think ahead to ensure your transitions are easy.

Looking good,you can put a filler wire in between those twists that are 'empty' to make it more uniform before shrink it down.

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