• Make sure that the correct wire thickness is used for each power electronic component. If
wires are common ensure that the wire is thick enough to carry the total current. Too thin
wires will heat up and may start a fire. The same goes for relays. Be careful of cheap
relays. They can seize and start a fire. Use 0.5mm
2
of wire for every 5A of current. Also
check pin numbers of the relays as they differ from one manufacturer to the other. This
mistake may be costly!
• Solder each connection and use shrink sleeve rather than insulation tape. Stagger solder
joins so that they do not sit next to each other. Cover connections and loose wires with PVC
or pigtail sleeve rather than insulation tape.
• Ensure that all electronic settings are correct before connecting the 10Way connecter.
Certain settings may damage equipment if not set to recommendations. Especially the coil
output trigger level. Follow the start-up procedure.
• Ensure a proper ground from battery negative to the body and from battery negative to the
Transmission. This wire must be thick enough to carry the current of all the equipment in
the car.
4.4 Sensors
There are three groups of sensors for speed and rpm sensing. Magnetic, Hall and Optic sensors.
Hall and optic sensors both give a square wave output and are treated exactly the same. They
have electronic components in the sensor which convert the signals to square wave. The Hall
sensor uses magnetic field where optic uses infrared light. In both cases a beam is broken and
detected. Magnetic sensors are just a magnetic coil around a magnet. The metal point passing this
sensor induces a spike which has then to be converted to a square wave so that the processor
can work with it. These sensors have different inputs on the TCU that is why the harnesses differ.
They have different supply voltages which is selectable with jumpers on the PC Board. See the
drawing for correct settings.
4.4.1 Magnetic sensors
1. These sensors provide only a voltage spike to the TCU. The TCU will convert this spike to a
usable square wave to be used by the micro processor.
2. Each sensor has its own positive and negative wire from the TCU. Do not connect
magnetic sensors with common ground wires. The negative is connected to 5V and will
damage the TCU if connected to ground. Disconnect and isolate it first.
3. Make sure that the positives and negatives of the sensors are connected correctly.
4. In certain cases a 1 K ohm resistor may be connected between positive and negative to
reduce spikes in the signal.
5. Connect the screened cables from the TCU as close to the sensor as possible. Do not let
single open wires run along the spark plug wires or the coils as this will induce interference
in the TCU causing erratic firing.
6. Do not connect the screen to the Transmission. It is already connected to the body at the
TCU.
7. Do not connect other devices to this pickup as it will interfere with the signal to the TCU.
Testing a Magnetic sensor
These sensors have a wired coil with a magnet. They normally have two wires. Some do have 3
wires which have an earth which is not connected to the coil. The Coil resistance vary from 150
ohm to 1200 ohm typically. If you swap the tester wires around you would measure the same
resistance value. To test for positive put the meter on milli volts DC. Connect the wires to the coil
of the sensor. Move an iron object to the sensor and look closely at the polarity indicator. If it
indicate positive when moving closer to the sensor and negative when moving away from the
sensor, it means that the red wire of your meter is on the positive of the sensor. If it is the other
way round, then the black wire is on the positive of the sensor.
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