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Fusion MS-RA770 wiring diagram
Fusion Apollo MS-RA770, 10.8–16 V DC, four audio zones and four amplifier channels. Yellow main supply requires 15 A protection and red ACC a separate 1 A fuse. Standby can draw up to 200 mA; isolate yellow for storage.
- Compatible systems
- 12 V
- Continuous draw
- 5 A
- Surge current
- 15 A
Wiring diagram
How the MS-RA770 is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
12 V system
- Wire
- 2.5 mm² · 13 AWG
- Example fuse
- 10 A
- Design current
- 5 A
- Voltage drop
- 1.8%
Sized against ABYC E-11. The design current is the part's continuous draw. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 2.5 mm² (13 AWG) marine cable
- Terminations for 2.5 mm² cable, matched to the equipment's screw terminals, leads or studs
- 10 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. GUID-21C6C2B1-A013-4F54-8201-0015D54B9856 v7 \u2014 July 2022), checked 2026-10-01. Manufacturer documentation →
Model and input limits
The Apollo MS-RA770 operates from 10.8–16 V DC and has a specified maximum current of 15 A. Its four amplifier channels are advertised at 70 W maximum each, not 280 W continuous battery draw. The RMS ratings depend on speaker impedance and test conditions. The four audio zones are not four independent high-current power inputs.
Three wires with different jobs
The catalog `+` maps to the yellow main supply wire, `−` to black ground, and `ACC` to the red switched/enable supply. Yellow requires a 15 A circuit breaker or, if unavailable, a 15 A fuse. Red requires its own 1 A fuse even when joined to yellow after a common switch. Red must be powered for the stereo to turn on; it is not a speaker output or a route for the amplifier’s full current.
Shutdown and cable extensions
Turning off the stereo with red or the front button leaves standby consumption of up to 200 mA; interrupt yellow when storing the boat to prevent battery drain. The table lists muted current below 900 mA. For yellow and black extensions the manual specifies 14 AWG, increasing to 12 AWG beyond 1 m; red extensions use 22 AWG. Check the full installation for voltage drop and circuit protection.
Audio, networks and drawing limits
External amplifiers need their own power circuits and share the stereo’s ground reference for the blue amplifier-on signal. Speaker pairs, RCA outputs, PartyBus and NMEA 2000 connections are omitted from this power-only drawing. The IPX7 rating applies to the front when installed correctly, not exposed rear connectors. Confirm speaker impedance, zone assignments and network configuration before commissioning; modeled listening hours and average current are not guaranteed by the 15 A fuse rating.
Source: manufacturer document — power wiring printed/PDF pp. 5–11; speaker/network diagrams pp. 11–15; technical specifications pp. 21–22.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with MS-RA770 connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
Fusion Apollo MS-RA770, 10.8–16 V DC, four audio zones and four amplifier channels. Yellow main supply requires 15 A protection and red ACC a separate 1 A fuse. Standby can draw up to 200 mA; isolate yellow for storage.
- Compatible systems
- 12 V
- Continuous draw
- 5 A
- Surge current
- 15 A
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
+
positive · input
−
negative · input
ACC
signal · bidi
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
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Plan your installation with MS-RA770.
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