1966 Ford Mustang - Project '66 - Audio Upgrades

8 The Custom Autosound 6x9 speakers were installed next. We installed them in the inboard stamped opening on either side of the factory single 6x9 opening in the center. Again, small mounting holes were drilled for securing the speakers, but no major cutting was involved. After 35-plus years, many hardtops already have 6x9 holes drilled, so someone may have saved you a step. Here you can see where the speaker and CD-changer wiring is tie-wrapped up out of view for a super-clean installation.

9 The speaker grilles show how the speaker assemblies are secured. The package tray is literally sandwiched between the speaker and the speaker grille. Tighten the mounting screws evenly to prevent distortion of the grille, yet allow for a snug speaker fit for optimum sound.

10 The door speakers are actually the most difficult to install and wire, but the looks and sound are worth it. Since our hardtop didn't originally have the Deluxe courtesy light or door speakers, the doorjamb and the door face was drilled to accept the reproduction wiring harness from Virginia Classic Mustang. A right-angle drill will work, or you can drill from within the door (bare shell) and from the opposite side of the cowl panel.

11 If you don't have a right-angle drill, you can drill from this opening in the cowl-side panel. Route the wiring through this opening and make the proper connections. The ground lead screwed to the cowl is for the courtesy light, while the pair of wires routed up are the speaker wires.

12 This little double-U-shaped clip is how the factory routed the speaker and courtesy light wiring to prevent entanglement with the window regulator. Since they're not visible with the door panel on, any modern equivalent will accomplish the job. We found these at a hardware store in packs of 10 (you only need a few per side).

13 Here's a clip, as it should be installed. The narrow side grips the door skin and the larger U holds the wiring harness. Make sure there's no slack that will get caught in the window mechanism; route your wiring inside the door. Notice the speaker hole has been cut and the speaker leads are protuding.

14 Using the speaker grilles and the hole template included with the grilles, estimate the mounting areas on the 4x6 door speakers and install the nut clips. We had to drill a few new holes in the ends of our speaker mounting plates so they would mount correctly, but that's because of the 4x6 speaker's universal mounting nature. The stock speakers are an odd size (if you can still find them) and don't have the sound quality of these 4x6 plate speakers, so they'll take a little extra work for better audio output.

15 Connect the 4X6 speaker to the door harness, but don't install the speakers yet. Leave them out so you can test the system.

16 Here's the best way to connect the door speakers, which is similar to an '87-'93 Mustang speaker wiring. Simply tap the door speakers into the dash speaker wiring so they can share the signal (just like a late-model). The speaker wires at the top are from the 4x10 in the center of the dash, while the wiring at the bottom of the picture is from the stereo itself. The white speaker wire you see is from the door speakers (connected to the factory door harness under the dash), then tee'd into the dash speaker wiring (shown in my hand).

17 After testing the stereo and making sure all connections are sound (no pun intended), you can install the door speakers. The speaker grilles aren't included but are standard Mustang items. We purchased ours from Virginia Classic Mustang when we ordered the door wiring. Lining up the speakers and the door grille is quite a chore and may require a helper, so be patient.

18 Last, mount the stereo into the dash face. Barring the correct deep socket, you can carefully tighten the mounting nuts with an adjustable wrench. Don't let the stereo's weight be supported by only the shaft mounting nuts; install the stereo support strap as well. We didn't like running a self-tapping screw into our cowl (plus the wiper transmission would hit), so we fabricated the support strap to mount to the lower edge of the dash behind the ashtray and it worked perfectly.

19 Now for the final effect: Custom Autosound's reproduction radio knobs that mimic the look of the factory knob. Here you can clearly see the AM radio dial faceplate too. The sound quality is on par with any mid- to high-end factory system, and we're constantly amazed at how many stations the tuner can pick up. In all, this is a job well worth the afternoon in the garage.