Begin by locating the main fuse block under the left-side panel. This is the primary power distribution point for the touring model’s electrical system. Disconnect the battery negative terminal before initiating any inspections to prevent short circuits or accidental activation of components.
Trace the ignition wiring from the handlebar controls to the engine control module (ECM). The left-hand switch assembly carries critical circuits–ensure the pink wire (key switch output) connects directly to the ECM without splices or damage. Corrosion here causes intermittent starting issues. Verify continuity with a multimeter; resistance should not exceed 0.5 ohms.
The lighting subsystem relies on the front and rear harness plugs. Inspect the 12-pin connector adjacent to the rear turn signals–melted terminals indicate overloaded circuits. Replace the entire harness if pin discoloration or pitting is visible. Load testing should show 11.8V minimum under full beam operation.
Check the charging system voltage at the stator plug while the engine runs at 2,000 RPM. Measured voltage between the yellow wires should read 13.5–14.8V AC. Readings outside this range necessitate stator replacement. Use dielectric grease on connectors to prevent moisture ingress.
For troubleshooting non-start conditions, focus on the security module beneath the seat. Confirm the violet/white wire receives battery voltage during ignition-on state. A blinking security light points to failed communication with the key fob transceiver, requiring module reset or replacement.
Electrical Schematic for Harley Touring Models: Decoding the 2013-2015 Variant
Locate fuse F21 (10A) on the left-hand fuse block–this feeds the farkle bar accessory circuit and TSM (turn signal module). If accessories fail, test F21 continuity first; corrosion at the junction behind the left side cover mimics blown fuses. Probe terminals 8 (purple) and 9 (black/orange) on the 12-way ignition connector with a multimeter set to diode check; readings above 0.5V indicate a faulty run/stop relay.
Critical Harness Junctions
Disconnect the main 30-pin connector at the ECM before probing–back-feeds from the VCM (vehicle control module) can scramble live data. Focus on the grey 6-way connector near the battery tray; pins A (red/green) and B (black) carry ignition power to the gauge cluster. Check resistance between pin C (yellow/blue) and chassis ground–values below 1Ω confirm a solid ground path; spikes trigger phantom ECM errors.
Replace the stock flasher relay with a 3-pin electronic unit only after verifying CAN bus voltage at the OBD-II port. Clip the white connector at the rear fender; pins 1 (blue/white) and 2 (grey) must stabilize at 2.5VDC (±0.2V) during idle key-on. Voltage drops below 2.2V indicate a short in the left-hand switch cluster–inspect the horn relay coil for chafed grey/white wires wrapping behind the headlight bucket.
Finding Key Electrical Link Points on a Touring Model
Begin by removing the right-side saddlebag to expose the battery compartment. Behind the fender’s plastic cover, you’ll find the central fuse block mounted directly to the frame–this is the primary hub for high-amperage feeds. Trace the thick red cable from the battery’s positive terminal; it terminates here before splitting into circuits for the starter, lighting, and accessories.
Under the seat, the main 32-pin connector links the front and rear electrical networks. Disconnect the seat by releasing the two T27 bolts securing it; the connector sits just below, tucked against the frame rail. Label each pin with masking tape–misalignment here disrupts fuel pump operation, turn signals, and instrument readings.
- Battery positive cable (red, 6 AWG) → Fuse block input
- Ground strap (black, 4 AWG) → Frame stud near swingarm pivot
- 32-pin harness (gray) → Under-seat bulkhead
- 12-pin accessory plug (black) → Behind left fairing
Behind the left fairing, a secondary 12-pin plug handles accessories like heated grips and auxiliary lighting. Remove three Torx T25 fasteners to drop the fairing; the plug sits adjacent to the turn signal module. Match connectors using the engraved numbers–mismatching them here can trip the TSM (turn signal module) into failsafe mode.
On the right handlebar switchgear, the throttle position sensor (TPS) connects via a 4-pin weatherproof plug. Rotate the throttle grip to ensure free movement–binding here skews ECM readings, causing surging or stalling. Verify continuity between pins 1 (5V reference) and 3 (signal return) with a multimeter; resistance should read 0.5–1.5 kΩ at closed throttle.
- Disconnect negative battery terminal first
- Tag each connector with its functional label
- Check TPS resistance at idle and wide-open positions
- Reconnect accessory plugs before restoring power
Step-by-Step Guide to Tracing the Headlight Circuit in the Harley Touring Schematic
Begin by locating terminal 1 on the main fuse block, identified by its white/black (W/BK) wire connection in the factory electrical layout. This wire serves as the primary power feed for the low-beam function, branching from the 15-amp auxiliary fuse slot. Use a multimeter set to DC voltage (20V range) to confirm 12.8V+ at this point before proceeding–readings below 12V indicate corrosion or loose connections at the fuse or battery terminals.
Follow the W/BK wire downstream to the headlight relay, housed in the front harness connector beneath the fairing. Pin 85 on the relay (brown/yellow, BR/Y) carries the trigger signal from the handlebar switch assembly. Test continuity between this pin and ground while toggling the switch–absence of voltage suggests a faulty relay coil or broken wire in the switch circuit. Replace the relay if resistance exceeds 60 ohms.
| Wire Color | Harness Location | Typical Voltage (Key On) | Failure Symptoms |
|---|---|---|---|
| White/Black (W/BK) | Fuse block to relay (pin 30) | 12.8V–14.2V | No low beam, dim output |
| Brown/Yellow (BR/Y) | Relay (pin 85) to switch | 0V–12V (switched) | Relay clicks but no beam |
| Light Blue/White (LB/W) | Relay (pin 87) to bulb | 0V or 12.8V (activates low beam) | Intermittent or single-side failure |
Trace the light blue/white (LB/W) output wire from relay pin 87 to the headlight bulb socket. Inspect the connector for melted pins or green oxidation–clean with electrical contact cleaner if resistance exceeds 0.2 ohms. The factory harness splits here for dual-filament bulbs; verify both LB/W wires connect to the H4 bulb’s low-beam terminal. A common failure point is the in-line connector near the lower fork–secure with dielectric grease if exposed to moisture.
For high-beam tracing, shift focus to the dark blue (DK BLU) wire from the handlebar switch. This routes through the left-hand control module before terminating at relay pin 86. Test for voltage drop across the circuit by back-probing the relay connector with ignition on–expected values are 0.1V loss per 10 feet of wire. If high-beam operation is erratic, bypass the switch with a 12V test lead to isolate failures in the control module’s micro-switch.
Diagnosing Electrical Faults with the Touring Bike Circuit Blueprint
Begin by isolating the accessory fuse block if the auxiliary lights fail completely. The color-coded reference manual highlights a 10A fuse linking the battery positive terminal to the switch–verify continuity here before proceeding. Failure often stems from corrosion at the fuse holder tabs, not the fuse itself; clean contacts with a wire brush and dielectric grease to prevent recurrence. If power persists beyond the fuse but fails at the switch, trace the violet wire from the switch output to the load connector–this path commonly severs near the pivot joint due to repeated flexing.
Check the ignition circuit for parasitic drain by disconnecting the negative battery post and inserting a multimeter in series. Acceptable draw should not exceed 50mA; readings above this threshold indicate a rogue module or shorted relay. The schematic identifies the TSM (turn signal module) as a frequent culprit–remove its connector and retest. If current normalizes, inspect the module’s ground path through the brown wire leading to the frame, ensuring it terminates at a clean, unpainted surface. A faulty TSM often exhibits heat damage at the solder joints–replace if discoloration is present.
For intermittent starter issues, follow the heavy red cable from the solenoid to the starter motor, probing each connection with a voltmeter while cranking. Voltage drop exceeding 0.5V across any joint confirms high resistance–disassemble, clean, and crimp fresh terminals. The neutral safety switch, denoted in the layout as a pink/black wire, must close when the transmission engages; bypass it temporarily to confirm function if no-start persists. Faulty switches typically stick due to internal corrosion–apply contact cleaner through the access port before replacement.
LED turn signals flashing at double speed indicate either a burned-out bulb or faulty flasher relay. The relay’s location is annotated on the bottom right of the schematic near the rear fender–A/B testing with a known-good relay isolates the issue. If the relay checks out, pursue the dark green wire from the socket to the bulb, verifying no chafing occurs where it passes through the frame rail. Ground-side failures manifest differently; probe the black wire at the socket while the signal is active–zero voltage confirms an open ground, often resolved by re-securing the socket’s mounting bolt to bare metal.
Audio system malfunctions typically trace back to the accessory relay or speaker grounds. The relay’s 30A fuse should be inspected first–it’s housed in the front fuse box, labeled “ACC.” If intact, follow the orange wire from the relay output to the audio controller, confirming 12.6V at the connector with the ignition on. Ground faults frequently occur at the speaker mounts; detach the terminal, abrade the mounting surface, and reattach with a star washer. For distorted output, swap speakers left-to-right–consistent distortion on both channels implicates the amplifier, while isolated distortion suggests a wiring or ground issue specific to one channel.