MoTeC M84 - Manual (Page 22)

20 Installation MoTeC
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
won’t 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.
Soldering the terminal is a last resort if the correct crimping tool is not
available. Soldering will cause a stress point where the solder wicks up the
wire which is likely to fracture unless all movement is avoided. Solder flux can
also cause corrosion and may affect the contacts.
Terminal Damage
The various connector terminals are easily damaged if probes are inserted
into them. Do not insert probes of any kind into the terminals. If checking a
circuit for continuity, gently touch the side of the terminals only, or preferably
attach a mating connector.