Buell 2005 P3, Service Manual, Page: 375 / 426

2005 Buell P3: Electrical 7-23
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IGNITION COIL 7.9
GENERAL
See Figure 7-24. The ignition coil is mounted on the frame
underneath the fuel tank on left side above airbox.
The ignition coil is a pulse-type transformer. Internally, the coil
consists of primary and secondary windings with a laminated
iron core. The contents are sealed in a waterproof insulating
compound. The ignition coil is not repairable. Replace the unit
if it fails.
The low-voltage ignition primary circuit consists of the coil pri-
mary winding, ignition module and battery. When the circuit is
closed, current flows through the coil primary winding creat-
ing a strong magnetic field in the iron core of the ignition coil.
When the ignition module receives a signal from the cam
position sensor and trigger rotor, the ignition module inter-
rupts (opens) the ignition primary circuit, which causes the
magnetic field in the coil core to collapse.
The collapsing magnetic field induces a high-voltage electri-
cal discharge in the ignition secondary circuit, which consists
of the coil secondary winding, spark plug cable and spark
plug. The high-voltage discharge produces a spark to bridge
the electrode gap of the spark plug.
The ignition coil fires the spark plug at the end of the com-
pression stroke (no-waste spark).
TROUBLESHOOTING
Follow the troubleshooting procedures listed under 7.8 IGNI-
TION MODULE AND CAM POSITION SENSOR if the engine
will not start, is difficult to start or runs roughly. Also check
condition of the spark plug cable. Insulation on cable may be
cracked or damaged allowing high tension current to short to
metal parts. This problem is most noticeable when cable is
wet.
If poor starting/running condition persists, check resistance of
ignition coil primary and secondary winding using an ohmme-
ter.
Ignition Coil Primary Circuit Test
1. Remove ignition coil.
2. Set ohmmeter scale to RX1.
3. See Figure 7-25. Using gray female probes and patch
cord from TEST CONNECTOR KIT (Part No. HD-41404),
place multimeter wires on primary coil windings. See
7.3
DIAGNOSTIC CHARTS .
4. Check for primary coil winding resistance.
a. Normal resistance range is 0.4-0.6 ohms.
b. See TEST RESULTS on the next page if resistance
is not within normal operating range.
Figure 7-24. Ignition Coil (Left Side)
Figure 7-25. Ignition Coil Primary Resistance Test
7796
1. Connector [83]
2. Mounting screws (2)
3. Spark plug post
3
1
2
7797