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Jabsco PARMAX HD4 Q401J-115S-3A wiring diagram
12 V, 4 GPM freshwater pressure pump with 40 PSI shut-off, up to 10 A at 40 PSI and a required 15 A fuse. Fit the specified inlet strainer; intermittent duty. Catalog draw is the maximum published operating point, not average faucet use. Terminal limits are protection-based planning bounds.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V
- Continuous draw
- 10 A
Wiring diagram
How the PARMAX HD4 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.
The Q401J-115S-3A example uses the specified 15 A fuse and 10 A maximum running current. Verify actual cable length, pressure-switch operation and plumbing. The fuse does not establish motor startup current. Manufacturer installation manual
Edit this wiring exampleCable 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.
10 ft one way
12 V system
- Wire
- 11 AWG · 4 mm²
- Example fuse
- 15 A
- Design current
- 10 A
- Voltage drop
- 2.2%
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.
The Q401J-115S-3A example uses the specified 15 A fuse and 10 A maximum running current. Verify actual cable length, pressure-switch operation and plumbing. The fuse does not establish motor startup current. Manufacturer installation manual
Supporting parts
- 20 ft total of 11 AWG (4 mm²) marine cable
- Terminations for 11 AWG cable, matched to the equipment's screw terminals, leads or studs
- 15 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. Q401J-115S-3A Rev B, 12/2025; HD IOM 81000475 Rev C, 07/2021), checked 2026-10-01. Manufacturer documentation →
Pressure water at the taps
Q401J-115S-3A is the 12 V PARMAX HD4 freshwater pump: 4 GPM open flow and 40 PSI shut-off. It starts as an open tap lowers system pressure and stops after the taps close and pressure recovers. Its flow at an open outlet is not a promise of 4 GPM through a restrictive shower head. This exact suffix matters; other HD and HotShot models have different pressure and electrical ratings.
Supply, switching and protection
Use a dedicated switched positive feed to the red lead and a negative return to the black lead. Fit the specified 15 A fuse and retain access to the pump isolator. The exact datasheet gives a maximum operating point of 10 A at 40 PSI, which is the catalog's sizing draw. The fuse is protection, not operating consumption; no starting surge has been invented.
The pump's short factory leads are 14 AWG. They do not establish the required size for an arbitrarily long boat run. Select extensions for ampacity and voltage drop over the complete circuit, using the HD installation manual's length table. Published operation is 9–13.6 V. A battery voltage reading alone does not show what reaches the pump while it runs. The terminal limit is a protection-based planning bound.
Plumbing that lets the pump prime
Fit the required strainer before the inlet, keep suction joints airtight, and use the correct quick-connect fittings with their retaining clips fully engaged. Leave space to withdraw those clips and clean the strainer. Arrange mounting and hose support so vibration is not carried into rigid plumbing. The exact datasheet permits self-priming up to 2.4 m, but a short, unrestricted suction route gives more margin.
An accumulator can smooth small intermittent demands and reduce rapid cycling; it is not a substitute for finding a leak. The pump has thermal protection and is intended for intermittent duty. Its ability to tolerate dry operation does not make an empty tank a useful normal operating condition.
First fill and fault checks
Fill the tank, open the outlets and let trapped air clear, then close them and confirm the pump stops at pressure. Inspect every joint under pressure. If it cycles with all taps closed, check leaks, a dripping tap and the check-valve path. If it runs without useful flow, inspect the inlet strainer and suction-side air leaks before changing the pressure switch. A hot motor that stops and later restarts may be reaching thermal protection; investigate restriction and excessive duty rather than bypassing it.
Manuals and evidence
Exact HD4 datasheet, pp. 2–3, establishes the suffix-specific ratings and required strainer. PARMAX/HotShot HD installation manual covers installation, wiring tables, priming and maintenance. Both downloads are indexed in the marine evidence ledger.
Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
12 V, 4 GPM freshwater pressure pump with 40 PSI shut-off, up to 10 A at 40 PSI and a required 15 A fuse. Fit the specified inlet strainer; intermittent duty. Catalog draw is the maximum published operating point, not average faucet use. Terminal limits are protection-based planning bounds.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V
- Continuous draw
- 10 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
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 — the US reference, and what Transport Canada accepts as an alternative to TP 1332 for pleasure craft under 24 m. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
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