AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 16)

Page 16 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
Side View. After crimping, be sure
to do a pull test to make sure the
terminal is properly installed.
Electronic Wiring Conventions
A proper wiring job includes proper termination of the wire at the sensor. The wire terminal end
must be moisture tight where it plugs into the sensor and it must have strong, electrically sound
terminals. The preferred method of securing a wire to a terminal is to use a crimp terminal with
NO solder. It is important to use the proper crimping tool for sound terminal construction.
Plastic terminal plugs must have moisture tight seals. Inspect each plug to make sure the seals
are in place. Also, before the plug is installed on the sensor, apply a dab of di-electric grease in
the terminal slots to further aid in corrosion resistance.
If a splice into a wire must be made and no solder-less terminals are available, then you must
properly solder the splice.
Noise can be a serious problem and can cause intermittent misfiring of the engine. Every
precaution should be taken to prevent interference to the ECU‟s operation. Resistive plug leads
are REQUIRED, and shielded cables from the crank and cam angle sensor inputs are highly
recommended. All racing AEM EMS wire harnesses come with properly shielded cables and are
color coded for easy identification of circuits. They are also shrink wrapped for abrasion
protection. The crank and cam angle sensor wire has a bare wire running down the length of it.
It is NOT terminated at the sensor end of the cable because we ground it at the plug end of the
harness. DO NOT GROUND THIS WIRE! This will cause a condition called ground looping
and will remove any noise protection the cable has.
To eliminate or reduce the chance of EMI, wires that carry high current must run in twisted pairs.
An example of this would be the power leads from a multiple spark ignition system. These
ignition systems can carry up to 100 amps for a couple milliseconds at the time of discharge,
which induces a strong magnetic field in close proximity of the wires.