AEM 30-71XX Infinity Stand-Alone Programmable Engine Mangement System Full Manual - Manual (Page 332)

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© 2014 AEM Performance Electronics
Infinity User Manual
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 AEM Infinity 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.
The routing of the wire loom is critical to EFI system performance and safety. The following safety
considerations should be made when installing the wire loom:
Heat protection: the loom should be placed away from or insulated from sources of heat.
The obvious item(s) that should be avoided are the exhaust manifolds, EGR delivery
tubes, and turbochargers. If it is absolutely necessary to route a wire in close proximity to
any of these items, then a suitable insulator must be used.
Noise suppression: do not route wires near the HT leads. For coil-on-plug ignition
systems this is not as critical.
Moving component protection: route wires away from moving components such as fans,
the blower belt, or the throttle linkage. Also, make sure the wires are not under any strain
when the engine is at full deflection on the motor mounts. (We have seen map sensor
wires disconnect while under full acceleration because the motor mounts were bad.)
Never have the wires in exposed bundles throughout the engine compartment. A
professional harness has shrink tube over it to resist abrasion and chemical damage to
the wire loom.