The engine gauge feed is next....
The engine gauge feed is next. We call this an engine gauge feed, but it also connects to the starter solenoid, which enables us to activate the starter. When you turn the key to "Start," power flows through one of these two wires to close the solenoid contacts, which channels power directly from the battery to the starter.
Power also flows to the ignition...
Power also flows to the ignition coil during cranking via the solenoid. Three engine-gauge feed wires go to the coolant-temperature sender, oil-pressure sender, and ignition coil.
Dave Toth lays out the main...
Dave Toth lays out the main wiring loom, which goes behind the dashboard.
The main wiring loom is fed...
The main wiring loom is fed into the dashboard. Instrument cluster connections, naturally, are positioned at this opening. Get a grasp of what connections you are dealing with, and make sure they're where they belong.
The fuse box on '65-'66 Mustangs...
The fuse box on '65-'66 Mustangs is located on the lefthand side above the kick panel. Dave takes extra care not to pinch any of the wires behind the fuse box. The fuse box's two hex-head sheetmetal screws can penetrate wire insulation, making an ugly short circuit.
The headlight-harness feed...
The headlight-harness feed begins at the main wiring loom behind the dashboard on the far lefthand side.
Push the firewall plug through...
Push the firewall plug through until the retainer clips pop through the firewall. This is the way the pins should look.
The windshield-wiper switch...
The windshield-wiper switch installs like this. JMC Motorsports uses a special tool to tighten the column.
You can order this tool, and...
You can order this tool, and other switch collar tools, from JMC. Connect the leads and install the switch. The knob is retained with an Allen screw.
The headlight switch is next....
The headlight switch is next. A gang plug gets the job done here. Position the switch in place and tighten the collar with a common screwdriver or the special tool mentioned earlier. Install the headlight switch knob and shaft. Push the shaft all the way in and turn until the shaft seats and locks.
The engine gauge feed firewall...
The engine gauge feed firewall plug installs mid-firewall. Behind the dashboard, there are pigtail leads for accessories and the automatic transmission indicator light.
Push this plug through the...
Push this plug through the firewall until the retainers click. It should look like this installed.
Live Wires
Talk about fast relief from wiring pain. Mustangs Plus makes it a cakewalk, with identical factory replacement wiring. A classic Mustang's electrical system consists of four basic areas. The main wiring loom is located behind the dashboard. From the firewall forward is the firewall-to-headlamp loom. For '65-'66, the engine gauge feed runs from the firewall to the engine and starter solenoid. The taillight harness runs from the dashboard to the trunk area. For '67-'68, the story isn't much different. Basics remain the same for '65-'68.