Product Description
Custom Autosound USA-850 for a 1973-89 Mercury
Custom Autosound USA-850 for 1973-89 Mercury – The Ultimate Radio Upgrade
Owners of 1973-89 Mercury vehicles know the value of a classic ride, but factory radios from this era often lack the modern features drivers want today. That’s why the Custom Autosound USA-850, available from Vintage Car Radio, is the perfect solution. Designed to fit seamlessly into your Mercury’s dashboard, this radio delivers advanced technology while preserving the original classic look.
The USA-850 is packed with features, including built-in Bluetooth connectivity for wireless music streaming and hands-free calling. Whether you're cruising in your Mercury Cougar, Grand Marquis, or any other model from this era, you can enjoy your favorite playlists, podcasts, or take calls without distractions.
For those who prefer traditional radio, the AM/FM tuner with 30 presets ensures easy access to all your favorite stations. The USB and auxiliary inputs provide even more options, allowing you to play music from MP3 players, flash drives, or other devices. Plus, the USA-850 is CD changer compatible, making it easy to add a CD player if desired.
With 300 watts of power (75 watts per channel), this radio delivers exceptional sound quality. Additionally, the four-channel RCA pre-outs and subwoofer output give you the flexibility to upgrade your sound system with amplifiers and speakers.
Best of all, the Custom Autosound USA-850 is designed to fit perfectly into the original dash opening of your 1973-89 Mercury, so no modifications are needed. If you're looking to upgrade your Mercury’s sound system while maintaining its classic aesthetic, Vintage Car Radio has you covered with the Custom Autosound USA-850—the perfect blend of retro styling and modern performance.
Specifications
• 4 programmable screen options
• Working analog dial
• Custom Fit In Dash
• 6-volt RCA Pre-Outs and dual subwoofer pre-outs
• DSP EQ
• Subwoofer control
• Bass, treble, mid
• Fader/balance
• Loudness on/off
• CD Controller
• RCA AUX in
• Bluetooth
• 75W X 4 Peak (300W max)
• PLL Tuner
• Power Supply 12 VDC negative ground
• Speaker impedance 2-8
• 4 lbs shipped
• Shipping box 12 X 11 X 5
• Fits all CAS current applications (400+)
USA-850 for a 1973-89 Mercury: Your Questions Answered
Is this radio made specifically for the 1973-89 Mercury?
This version is built for the 1973-89 Mercury and is made to fit the factory radio opening. Custom Autosound says its radios fit without altering or cutting the original dash.
Does it matter if my 1973-89 Mercury has factory air?
Select Yes or No under Factory Air so we send the correct setup for your 1973-89 Mercury's dash.
How does the USA-850 handle phone audio and connections?
You can adjust bass, treble and midrange or choose a DSP EQ preset (Flat, Classic, Pop or Rock). It has a rear RCA input and controls the optional CD-1 single CD player, and installation uses a simple 3-wire power harness.
What do I get with the USA-850 in my 1973-89 Mercury?
The DigaDial display gives you 4 screen choices, including a classic analog dial with a red needle that glides across the stations, or an all-digital RDS display. Custom Autosound rates it at 75 watts x 4 peak (300 watts max), with 6-volt RCA pre-outs and dual subwoofer pre-outs.
What about older positive-ground electrical systems?
Choose your system under Voltage (12 Volt and 6 Volt) and Ground (Negative and Positive) when you order.
Is there a CD or Bluetooth upgrade?
Check the CD options on this page, which include Single Slave CD.
USA-850 specifications
- DigaDial selectable display (including working analog-style dial and digital RDS views)
- Bluetooth built in (streaming and hands-free calling)
- 300 watts peak power (75W x 4 peak)
- AM/FM stereo tuner with RDS
- 25 presets
- USB port for MP3/WMA/FLAC/WAV playback and phone charging
- Rear RCA auxiliary input
- Direct control for optional CD-1
- 6-volt RCA pre-outs plus dual subwoofer pre-outs
- Bass, midrange, and treble; DSP EQ (Flat, Classic, Pop, Rock)
- Front/rear fader and left/right balance; loudness
- Power antenna lead; digital clock
- 12V negative-ground; 2–8 ohm speakers
- Designed for original classic dash openings (vehicle-specific faceplate)
- Custom Autosound 2-year manufacturer warranty
USA-850 wiring and tech tips
Use this as a head-unit reference for power, ground, antenna, speakers, and amplifier connections. Always match the printed diagram that ships with your unit if it differs.
Power and ground (typical Custom Autosound harness)
| Function | Wire color |
|---|---|
| Ignition / ACC +12V | Red |
| Battery / constant +12V | Yellow |
| Ground | Black |
| Power antenna | Blue |
Ignition and power-antenna leads are commonly fused at 1A on the harness—confirm against the guide that ships with your radio.
Speaker wiring (typical)
| Speaker | Wire color |
|---|---|
| Left front + / − | White / White-Black |
| Right front + / − | Gray / Gray-Black |
| Left rear + / − | Green / Green-Black |
| Right rear + / − | Violet (or Purple) / Violet-Black |
USA-850 extras
Expect antenna, USB (playback and phone charge), Bluetooth microphone, optional CD-1 control, 6V front/rear RCA pre-outs, and dual subwoofer pre-outs. Use the rear RCA AUX for a wired player. Pick your DigaDial display style in the radio menu after power-up.
Suggested order for a 1973-1989 Mercury
- Disconnect the vehicle battery before any wiring.
- Connect ground first, then constant (yellow) and ignition (red).
- Connect the antenna plug and the blue power-antenna lead if your car has a power antenna.
- Wire all four speakers, matching polarity.
- If using an amplifier, run RCA cables from the front/rear (and sub on USA-740/USA-850) pre-outs.
- Reconnect the battery and test radio, speakers, and charging system voltage.
Tech tips for 1973-1989 Mercury
- This radio is sold for the factory Mercury opening used in 1973-1989 models—do not cut a modern DIN rectangle if you want a stock look.
- A poor ground is the most common cause of whine or weak audio; scrape paint at the ground point and use a star washer.
- If AM reception is weak, check the antenna mast, cable continuity, and that the antenna plug is fully seated.
- Vintage Car Radio does not install radios. If you are not comfortable with 12V wiring, use a qualified installer.
USA-850 manuals
Download the manufacturer guide for operation, safety, and the official wiring diagram. You can also browse our full library on the Manuals page.
Vintage Car Radio does not offer installation. The manuals are for do-it-yourself reference or to share with your installer.
Two-Year Custom Autosound Warranty
All Custom Autosound radios sold by Vintage Car Radio are backed by a 2-year manufacturer warranty from Custom Autosound.
Radios are checked before shipping. If something is wrong out of the box or under warranty, call us at 844-802-4499 or 574-226-6676 and we will help coordinate with the manufacturer.
Vintage Car Radio does not offer installation services. Refer to the Manuals and Wiring / Tech Tips sections for manufacturer guidance, or use a qualified car-audio installer.
FAQ — 1973-1989 Mercury USA-850
Will this fit my 1973-1989 Mercury without cutting the dash?
It is built for the original radio opening used on 1973-1989 Mercury models. Compare your dash opening and bezel to the product photos. We do not modify dashes in-house.
Does this radio have Bluetooth?
Yes—Bluetooth is built into the USA-850 for streaming and hands-free calling. The DigaDial display also offers selectable classic dial and digital views.
Do I need an amplifier?
Many owners run speakers directly from the radio. Pre-outs are there if you want more volume or a subwoofer later.
Do you install the radio?
No. Vintage Car Radio ships the unit and documentation; installation is DIY or by a shop you choose.
What is the warranty?
Custom Autosound radios include a 2-year manufacturer warranty. See the Warranty section for details.
Need help?
Call 844-802-4499 or 574-226-6676.
Specs
Wiring / Tech Tips
Manuals
Warranty
Two-Year Custom Autosound Warranty
All Custom Autosound radios sold by Vintage Car Radio are backed by a 2-year manufacturer warranty from Custom Autosound.
Radios are checked before shipping. If something is wrong out of the box or under warranty, call us at 844-802-4499 or 574-226-6676 and we will help coordinate with the manufacturer.
Vintage Car Radio does not offer installation services. Refer to the Manuals and Wiring / Tech Tips sections for manufacturer guidance, or use a qualified car-audio installer.
