MoTeC M880 - Manual (Page 26)

24 Installation
Wiring Reliability
The wiring is critical for reliable operation of the ECU. The following points will
help to ensure that the wiring is reliable.
Ground Wiring
One of the most common wiring problems is poor ground wiring.
The ground wire must be grounded properly to the engine block. There
should be no paint or anodising between the ground wire and the engine
block. Temporary wiring is likely to cause problems, use a proper eyelet
terminal that is securely crimped to the ground wire. Studs fixed in place by
Loctite® can also cause a problem as the Loctite® becomes an insulator.
These comments apply to both the ECU ground wire and the Ignition system
ground wire.
The ground wire must be at least 12# (3.3 mm 2 ) and must be kept as short as
possible.
Power Wiring
The power wire must be wired by the shortest path possible to the battery via
a 30 Amp relay and a 20 Amp fuse. The relay and fuse must be in good
condition and the wires must be crimped securely to the appropriate
terminals. The relay should be activated by the Ignition Switch. The ECU
power must NOT be fed directly from the Ignition switch because it probably
wont handle the required current.
The power wire must be at least 12# (3.3 mm 2 ) and must be kept as short as
possible.
Spark Plug Leads
The spark plug leads can cause interference in the ECU wiring. Keep the
ECU wires away from the plug leads wherever possible (at least 100mm). If it
is necessary to cross the plug leads, cross at right angles.
Terminal Crimping
Use the correct crimping tool for each type of terminal. Do a pull test on a
sample wire and terminal to verify that the crimp is sound. In theory the wire
should break before the wire pulls out of the crimp.
Most crimp tools are only designed for a certain range of wire sizes so be
sure to test the crimp with the particular wire size being used.