Product Description
The Desoto resembles some of the most famous cars in the film industry. The unique sophistication of the Desoto vehicles came supplied with some of the very first AM radio designs: a single speaker fixed in the dash, and a great reception system. This has become one of the main things that real car gatherers adore about the Desoto. The challenge for the devoted collector is maintaining that stock setup with modern sound features. Let’s face it, no matter how flawless your Desoto looks on the outside, you must have the quality sounds to go with it. When you are traveling down the open interstate with the top down listening to a static filled AM station through a single speaker, it just takes the ambiance away. No matter what, you just can't get awesome quality sound out of a noisy convertible with old technology. Still, all is not lost. The brilliant minds of Custom Autosound along with the makers at Ken Harrison Radios have a viable solution. The USA-740 unites that classic look with today’s technology.
Custom Autosound USA-740 Classic Car Radio With Bluetooth USA-740 Radio with Bluetooth Features:
- AM/FM Radio Bluetooth, USB & Auxiliary Inputs
- Option to Add CD-1, Single CD Player
- Bluetooth is Built Into the Radio
- Fits in your Original Dash Opening Without Cutting
- 3.5mm Aux Input on Front of Radio
- RCA Aux Input On Back
- Change Display Lettering Color
- Digital Tuner
- RDS Song/Artist Information
- 5 Channel RCA Pre-Outs w/ Subwoofer Control
- Separate Bass & Treble Control
- 5 EQ Presets
- Fader and Balance Control
- 15 FM & 10 AM Pre Sets
- Seek/Scan Function
- Back by a 2 Year Warranty from the Manufacturer
You can be sure that they have done their research, and you will discover that your modern sound is just an online order away. The unique Desoto utilizes a positive ground electrical structure; the vast majority of the original stereos available today only operate with a negative ground electrical structure. The installation of a customized USA-740 eliminates this along with all other obstacles instantly. The correct wiring system is already in place and Custom Autosound makes the transformation as simple as preparing a cup of tea with any and all potential concerns already taken care of for you. After installing the 740 system, you can enjoy the pleasures of pure sounds coming from that original look. It is a custom car marriage made in restoration ecstasy.
Some of the added and hidden features include:
- A Digital Tuner
- Numerical Song and Artist Data list
- 5 Channel Pre-Outs (RCA)
- Discrete Treble, Bass, and Subwoofer Controls
- 5 Presets for the EQ
- Stability along with Fader Controls
- 15 Pre-Sets for FM stations and & 10 for AM stations
- A Scan and Seek Function
Best of all Custom Autosound offers a USA-740 with a multi-year warranty. If you are one of the valued Desoto collector, you are going to love how the USA-740 has made the top-down-tune-playing-life just that much easier.
USA-740 IN DASH AM/FM for Desoto: Your Questions Answered
Do I need to modify the Desoto dash to install it?
This listing is the version made for the Desoto, 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-740 do?
The USB port plays MP3, WMA, FLAC and WAV files from a flash drive. There are two auxiliary inputs, a front mini jack and a rear RCA.
Will it keep the stock look of my Desoto dash?
Yes. It's built to keep the original look in the Desoto dash while adding modern features.
What can I add to my USA-740 IN DASH AM/FM for Desoto order?
You can add a front dual voice coil speaker, a rear 6x9 speaker pair (Custom Autosound 6x9 Speaker Pair and Upgraded Pioneer Speaker Pair), and a hideaway antenna right from the options above.
Can I add a CD player or Bluetooth?
Yes. The options include Single Slave CD.
My Desoto is 6-volt or positive ground. Can I still use this?
Choose your system under Voltage (12 volt and 6 volt) and Ground (Negative and Positive) when you order.
USA-740 specifications
- Bluetooth built in (streaming and hands-free calling)
- 300 watts peak power (45W x 4 RMS, 2-ohm stable)
- AM/FM stereo tuner
- 2 AUX inputs (3.5 mm front and RCA rear)
- USB port
- Direct control for optional CD-1
- 5-channel RCA pre-outs including subwoofer pre-out and control
- 15 FM and 10 AM presets
- 7-color LCD with dimmer; RDS station/song/artist display
- DSP EQ; auto-store presets
- Electronic tuning and volume; separate bass/treble; 4-way fader; L/R balance
- Power antenna lead; digital clock
- USA/EUR/JAP/RUS tuner capability (USA default)
- Custom Autosound 2-year manufacturer warranty
USA-740 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-740 extras
Expect antenna, USB, microphone (Bluetooth), CD-1, and subwoofer RCA connections in addition to front/rear line outs. Use the front 3.5 mm AUX or rear RCA AUX for wired sources.
Suggested order for a classic Desoto
- 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 classic Desoto
- This radio is sold for the factory Desoto opening used in classic 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-740 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 — classic Desoto USA-740
Will this fit my classic Desoto without cutting the dash?
It is built for the original radio opening used on classic Desoto 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-740 for streaming and hands-free calling.
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.
