Complete Electrical Wiring Guide for the 1968 VW Bus Model
Start with the fusebox layout. The original Type 2 models from this era use a twelve-position fuse panel mounted under the dashboard on the driver’s side. Fuses protect circuits in this order: left-to-right, top-to-bottom–positions 1 through 6 cover interior lights, horn, and ignition; 7 through 12 handle headlamps, brake lights, and turn signals. Label each fuse with its amp rating (typically 8A or 16A) and circuit function before removal. Cross-reference with a Bay Window manual if markings are faded; Splitties follow identical pin assignments.
Trace the main harness routing next. The bundle exits the fusebox, runs along the firewall’s upper edge, then splits near the steering column. One branch descends to the ignition switch; another arcs behind the glovebox to the light switch assembly. Two key splices often corrode: the bullet connector joining the headlamp harness (green/yellow stripe) to the main loom, and the joint feeding the rear license plate light (brown wire). Desolder and replace any brittle or discolored joints with marine-grade solder and heat-shrink tubing.
For engine bay components, identify the generator or alternator circuit first. Models equipped with a 12V system use a 40A alternator wired directly to the battery positive via a heavy-gauge red cable. The regulator (mounted on the firewall) controls voltage via a smaller brown/white lead. Check resistance between the regulator’s “D+” terminal and ground–values above 0.5 ohms indicate internal corrosion; replace the unit if readings fluctuate. Ignition coils differ: early models use a 6V coil with resistor wire, later ones include a ballast bypass for 12V cranking.
Focus on turn-signal wiring if lights flash erratically. The flasher relay (mounted behind the speedometer) uses two spade terminals–one feeds power, the other grounds through the turn-signal lever. A faulty relay often clicks rapidly without illuminating bulbs; test by jumping the terminals with a screwdriver. Verify bulb socket continuity (1156 rear, 1157 front) and ensure the brake light switch (green wire) isn’t cross-feeding the turn circuit. Replace sockets showing melted plastic or green oxidation.
Grounding points demand special attention. Primary grounds (battery negative, engine block, and chassis) use 10-gauge braided straps; secondary grounds for dash and tail lights rely on 16-gauge single wires. Locate and clean all chassis grounds–common failure spots include the rear hatch hinge, license plate mount, and passenger-door striker plate. Sand each contact point to bare metal, apply dielectric grease, and secure with stainless steel hardware. A single weak ground can manifest as dim lights, erratic gauges, or parasitic battery drain.
Restoring Electrical Schematics for Classic Transporters: A Hands-On Approach
Start by tracing the main harness routes under the dashboard. The central fusebox on early Type 2 models sits behind the lower glove compartment; it houses six fuses rated 8A for lights and 16A for accessories. Label each fuse with masking tape before disconnecting–match the existing numbers to the service manual’s fuse map to avoid misrouting.
Color-coding follows DIN 72551 standards but fades over decades. Use a multimeter on continuity mode to confirm circuits:
| Wire Color | Typical Function | Ohms Resistance (approx.) |
|---|---|---|
| Red/White stripe | Headlight high beam | 0.2–0.5 |
| Green/Black stripe | Left turn signal | 0.4–0.7 |
| Brown | Ground return | Near zero |
| Yellow/Red stripe | Ignition feed | 0.1–0.3 |
Replace any wire showing more than 1 ohm per meter.
Solder all connections with 60/40 rosin-core solder; avoid crimp terminals which corrode inside the frame tubes. Heat-shrink tubing over each joint prevents shorts against the chassis. Route harness bundles away from sharp edges–use split loom sleeving secured with zip ties every 10 cm.
The combination flasher relay sits left of the steering column; original units fail silently. Test by bridging terminals 49 and 49a with a jumper–if lights flash, replace the relay immediately. Aftermarket solid-state units fit the same mounting bracket and run cooler.
Inspect the voltage regulator beneath the rear bench seat; corrosion here causes dim lights or rapid battery drain. Clean the three-prong plug with contact cleaner, then coat each terminal with dielectric grease before reassembling. Reattach the battery ground cable last to prevent accidental shorts–a 6 mm bolt with star washer ensures solid grounding to the chassis rail near the rear taillight assembly.
Finding the Right Electrical Schematic for Your Classic VW Transporter
Start by identifying the exact variant of your vehicle. The Split Window, Bay Window, and early Bay models between 1967 and 1969 differ significantly in their electrical layouts. The most reliable source for factory schematics is the official Volkswagen repair manual for the Kombi, Camper, or Panel Van–these documents include variant-specific charts. If you lack the original manual, seek reprints from Bentley Publishers, Haynes, or Robert Bentley, Inc., as they reproduce Volkswagen’s original diagrams with accuracy.
The early Bay Window Transporter (chassis numbers 217-2000-001 to approximately 219-3000-000) uses a distinct fuse block layout and color-coding compared to later Bay models. Locate the color-coded index in the manual’s schematic section–this index lists wire gauges, insulation colors, and circuit destinations. Note that European models may feature different symbols or relay placements than North American versions, so verify the market specification before interpreting any chart.
If factory manuals are unavailable, consult restoration guides written for air-cooled Volkswagens. Works by John Muir (“How to Keep Your Volkswagen Alive”) or the “VW Transporter Bible” by Rob Hawkins include simplified schematics tailored to non-factory modifications common in restoration projects. These resources often highlight frequently troubleshot circuits like the charging system, ignition, or auxiliary lighting setups, which differ from later T2 models.
Online archives offer downloadable schematics, but exercise caution. Trusted repositories include:
- TheSamba.com’s Type 2 section, where members upload verified scans of original documentation.
- Volkswagen Classic’s official heritage portal, which provides legal PDF downloads for select vintage models.
- Manufacturer-specific forums for Westfalia and Devon conversions, where wiring adaptations for pop-top roofs or auxiliary batteries are documented.
Always cross-reference digital copies with physical guides to avoid mislabeled or corrupted diagrams.
When examining any schematic, prioritize the vehicle’s serial number over year designations alone. Wiring changes occasionally occurred mid-year, and the serial number plate (located on the dashboard or under the rear seat) will confirm the exact production batch. For instance, vehicles built after May 1967 introduced an alternator instead of a generator, altering the charging circuit layout. A mismatched schematic could lead to incorrect diagnoses of voltage regulator or ground issues.
Key Circuit Differences by Model Year Sub-Variants
- Early Bay (1967–early 1968): Uses a 6V or 12V generator, external voltage regulator, and a fuse block with fewer terminals than later models.
- Mid-1968 Bay: Transitioned to an alternator, internal regulator, and updated ignition switch wiring. Look for schematics labeled “Bay Window 1968 (2nd half)”–these reflect the shift in electrical components.
- Westfalia/Camper Models: Feature additional circuits for interior lights, auxiliary batteries, or electric refrigerators. Factory-approved add-on schematics are often appended in conversion manuals.
Trace circuits physically before relying on any guide. Use a multimeter to verify continuity and label wires at both ends–crumbling insulation or previous repairs often deviate from stock configurations. Pay special attention to the turn signal relay, flasher unit, and hazard light integration if your vehicle was imported, as European and US safety regulations mandated different wiring for these systems.
Troubleshooting Without a Matching Schematic
If no exact schematic exists for your configuration, methodically test circuits by isolating components. Begin with the battery-to-fusebox ground path, then move to the main power distribution point behind the dashboard. Check for splices or wire nuts–these are telltale signs of past modifications not reflected in any official guides. Label each verified connection and sketch a custom trace to document deviations. Store this alongside any future schematic references to streamline future repairs.
Step-by-Step Wire Color Coding and Connection Points
Locate the main harness bundle behind the dashboard’s lower panel. The red cable with a thin white stripe powers the ignition switch; trace it to the steering column’s terminal block. Connect this to the fuse box’s 10A slot using crimp connectors (size 18-22 AWG).
Identifying Key Circuits
The brown wire grounds the vehicle’s electrical system–verify its path by following it to the chassis mounting point near the driver’s side footwell. Strip ½ inch of insulation and attach it to a clean, unpainted metal surface using a ring terminal and an M6 bolt. Avoid splicing this line unless absolutely necessary.
For the lighting circuit, the yellow wire with a black stripe controls the headlights. Route it from the combination switch to the dimmer relay, then to the headlamp sockets. Use a multimeter to confirm 12V output at the relay before finalizing connections. Replace corroded terminals with new soldered joints for reliability.
Trace the green wire to the turn signal switch. This line splits into left (green/white) and right (green/black) branches–match each to the corresponding bulb socket, ensuring polarity aligns with the bulb’s base. Test the circuit with a 3W bulb before reinstalling lenses to avoid shorting.
Battery feed lines (thick red) require 8-10 AWG wire. Connect the positive terminal directly to the starter solenoid, then branch to the alternator’s B+ post. Secure all connections with adhesive-lined heat shrink tubing to prevent voltage drop. Inspect the ground strap between the engine block and chassis for wear.
Auxiliary Systems
The blue wire with a red stripe activates the windshield wipers. Run it from the switch to the motor assembly, adding a 20A inline fuse near the motor. If wipers operate sluggishly, check the motor’s commutator for carbon buildup and clean with 400-grit sandpaper.
For the fuel gauge, the pink wire connects the tank sender to the dashboard indicator. Calibrate the sender’s resistance (typically 0-90 ohms) against the gauge’s scale. Replace frayed wires with silicone-jacketed cables to withstand heat near the exhaust manifold.
Heater fan circuits (solid white) draw high current–use 12 AWG wire and a 30A fuse. Route the line from the fan switch to the resistor block, then to the motor. If the fan runs intermittently, bypass the resistor with a test lead to isolate faults. Seal all splices with dielectric grease to prevent oxidation.