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Appendix 5: Harness Fabrication
(leads)
Trim-To-Fit Harness
Lead kits use our custom low-noise, distributed inductance, plug wire that is not shielded. We have
no (zero) reports of noise problems from customers using this wire when properly installed and in
good condition. If you do hear spark noise, something is not installed or functioning properly. Plug
“clicking” noise over the radio is a useful maintenance signal. Something
is loose or worn and arcing - which causes radio clicking noise. Leads
should be kept separated. Do NOT bundle them together which can
cause them to be inductively coupled. Wire looms can be purchased at
auto parts stores, but a simple separator can be fabricated out of tie-
wraps a
nd ¼” segments of leftover MAP sensor hose.
Criss-Cross vs. Up-Down
It’s relatively immaterial whether you route plug leads in the traditional magneto criss-cross fashion
(one ignition wired to alternating upper and lower plugs) or one ignition firing all the upper plugs and
the other ignition firing all the lower plugs.
Organizing leads
Because plugs in each Bank fire simultaneously, the coil attachments, within
each Bank, are interchangeable. Example: Plug wires for cylinders 1&2 can
attach to either coil tower of Bank A. This flexibility can reduce congestion and
wiring cross-over at the back of the ignition when attachments favor routing to
the left and right sides of the engine.
Lead Fabrication - Trimming
The red outer jacket and the white inner layers are separated by
a reinforcing fiber weave. The conductive element is a spiral
wound wire around a Kevlar core (avoid when trimming). Use a
razor blade to trim the OUTERMOST red and fiber layers ONLY
3
/4” from the end, all the way around the wire. Avoid cutting
anywhere near the center core. The white insulation layer
separates easily as you twist the trimmed outer jacket.
Note 1: The center core is easily nicked and weakened by
contact with a Stripping tool or a blade. DO NOT use the wire
stripping station on the crimp tool
.
Cut Line - Cut thru
outer layer and the fiber
layer. Stay clear of the
center wire core.
