Product Description
Custom Autosound USA-850 for a 1973-77 El Camino
Common Questions About the USA-850 for a 1973-77 El Camino
Is this radio made specifically for the 1973-77 El Camino?
This listing is the version made for the 1973-77 El Camino, designed to go into the original dash opening. Custom Autosound says its radios fit without altering or cutting the original dash.
What can the USA-850 do?
Custom Autosound rates it at 75 watts x 4 peak (300 watts max), with 6-volt RCA pre-outs and dual subwoofer pre-outs. You can adjust bass, treble and midrange or choose a DSP EQ preset (Flat, Classic, Pop or Rock).
Why does the order ask about factory air?
The Factory Air option tells us which dash layout your 1973-77 El Camino has, so pick Yes if it has factory A/C.
Can I buy speakers and an antenna at the same time?
Add-ons offered here are a front dual voice coil speaker, a rear 6x9 speaker pair (Custom Autosound 6x9 Speaker Pair and Upgraded Pioneer Speaker Pair), and an antenna (Hideaway Antenna and Power Antenna).
What features does the USA-850 have?
It streams music and takes calls over Bluetooth. The USB port plays MP3, WMA and FLAC files and also charges your phone.
My 1973-77 El Camino is 6-volt or positive ground. Can I still use this?
The order form has Voltage (12 Volt and 6 Volt) and Ground (Negative and Positive) options, so set them to match your 1973-77 El Camino.
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 1973-1977 El Camino
- 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 1973-1977 El Camino
- This radio is sold for the factory El Camino opening used in 1973-1977 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 — 1973-1977 El Camino USA-850
Will this fit my 1973-1977 El Camino without cutting the dash?
It is built for the original radio opening used on 1973-1977 El Camino 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.
