Basic dash build and small rewire of my 65 Mustang
This video shows a basic dashboard rebuild and a small rewire on a 1965 Ford Mustang. The work focuses on replacing/upgrading the dash wiring, installing a simple fuse block and switches, tidying wiring, and testing electrical circuits for reliability.
Build Sequence
1. Plan and label existing wiring
Document the current dash layout, take photos, and label each wire and connector so reassembly is straightforward. Identify circuits to be updated and plan fuse/relay placement.
2. Disconnect battery and remove dash trim
Disconnect the negative battery terminal. Remove dash bezel, glove box, instrument cluster, and any trim panels to access the wiring behind the dash.
3. Remove or free old wiring harness
Carefully disconnect and remove the old or damaged dash wiring harness and components, keeping labeled wires organized. Cut only where necessary to preserve original connectors you plan to reuse.
4. Install new fuse block and locate relays
Mount the new fuse block in an accessible, protected location under the dash and mount relays where needed for high-current circuits. Route main power and ground leads from the battery/engine bay.
5. Run and connect new wiring for switches and gauges
Run new wires for switches, ignition, lighting, and instruments, using appropriate gauge wire. Make connections using soldered joints or crimped terminals, then insulate with heat shrink.
6. Install switches, ignition switch, and make ground connections
Mount toggle switches into the dash, install the ignition switch if being replaced, and ensure all grounds are secure and paint-free for a reliable return path.
7. Test circuits and troubleshoot
Reconnect the battery, test each circuit one at a time (lights, ignition, gauges, accessories). Use a multimeter to verify voltages and check for shorts or incorrect wiring.
8. Secure, tidy, and reassemble dash
Bundle wiring with zip ties or loom, secure harnesses away from heat and moving parts, reinstall the instrument cluster and trim pieces, and perform a final systems check.
Frequently Asked Questions
How long does a basic dash rewire typically take?
For a simple dash rebuild and small rewire like this, expect roughly 4–6 hours including labeling, removal, wiring, testing, and reassembly depending on experience and scope.
VIEW FULL ARTICLE →Do I need to replace the entire wiring harness?
Not necessarily. The video shows replacing or supplementing dash circuits with a new fuse block and targeted wiring where needed. Full harness replacement is only required for severely damaged or brittle original wiring.
VIEW FULL ARTICLE →What safety steps should I take before starting?
Always disconnect the negative battery terminal before working on the dash to avoid shorts and accidental starts. Label wires and take photos before disconnecting anything so reassembly is straightforward.
VIEW FULL ARTICLE →Can I use toggle switches for all dash functions?
Toggle switches work for many accessory circuits, but for higher-current items like headlights or fuel pumps you should use relays controlled by the switch so the switch only handles low current.
VIEW FULL ARTICLE →How should I protect and organize the new wiring?
Use proper gauged wire, route wiring away from heat and moving parts, bundle runs with split loom or heat-shrinked wraps, and secure with zip ties and brackets. Labeling each circuit at both ends helps future troubleshooting.
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Parts Used (9)
Aftermarket dash / engine bay wiring kit sized for classic Fords; used as the main replacement harness for dash circuits.
Supplemental wire for running switches, gauges, and accessories.
Replacement or rebuilt ignition switch used when reworking dash wiring.
Crimp and snap connectors for harness connections.