# Marine Alternator Repair Long Beach | Starters & Regulators | Long Beach Marine Electric

> Battery not charging with the engine running? Marine alternator and starter repair, regulators and charging-circuit faults at your Long Beach slip. Call now.

URL: https://longbeachmarineelectric.com/marine-alternator-repair/

Repair · Same-day callback

# Marine Alternator & Starter Repair

Battery doesn't charge with the engine running, slow cranking, or a clicking starter? Charging-circuit and starter faults found and fixed at the slip.

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)

-   Charging voltage under load
-   Voltage regulators & sensing
-   Ignition-protected marine alternators
-   Starter draw & voltage-drop tests
-   Lithium-safe charging
-   Same-day callback

Last updated: October 6, 2026

[Long Beach Marine Electric](/) connects boat owners with licensed, insured marine electricians for marine alternator repair and starter work: alternators that stop charging, voltage regulators that over- or undercharge, belts and wiring faults, and starters that click or crank slowly. On a boat, the alternator is the main charging source underway, so a quiet failure shows up as a dead bank the next time you start up.

## What happens on the first visit

1.  Battery voltage at rest, during cranking and with the engine running. A healthy charging system lifts battery voltage well above resting.
2.  Voltage-drop test on the alternator output and ground paths, and on the starter cables during cranking.
3.  Belt tension and condition, plus alternator mounting and connections.
4.  Regulator and sensing-wire check, including any external regulator and how the charge is split between banks.
5.  A written finding and a fixed price for repair or replacement.

## Not charging with the engine running

When the battery doesn't charge underway, the fault is usually in one of four places: the **belt** (slipping or broken), the **wiring** (a corroded output or ground connection, or a blown fuse in the charging path), the **regulator** (failed or mis-set) or the **alternator itself**. Measuring voltage at the alternator and at the battery under load separates them quickly. Replacing the alternator first, when a $10 connection was the problem, is the most common wasted spend.

## Marine vs automotive alternators and starters

Alternators and starters in engine compartments where gasoline vapor can collect must be ignition-protected, which is the marine requirement covered by SAE J1171 and USCG rules. An automotive replacement may fit the bracket but isn't ignition-protected, which is a fire and explosion risk on gas boats and a survey finding on any boat. Marine units are also built to resist salt-air corrosion.

## Alternators and lithium batteries

Lithium banks accept charge so readily that they can hold a standard alternator at full output until it overheats. If you've converted to lithium, or plan to, the alternator usually needs a DC-DC charger or a smart external regulator with temperature sensing. See [boat lithium battery conversion](/lithium-battery-conversion/).

## Insurance, warranty and who pays

Alternator and starter repair is owner-paid. Diagnosis usually takes about an hour at the slip. Rebuilding or replacing a unit depends on the engine, access and part availability, and you get a fixed written price before work starts.

## What's included

-   Charging-voltage test under load
-   Alternator output and ground drop test
-   Belt inspection and tensioning
-   Regulator and sensing-wire check
-   Starter draw and cable drop test
-   Ignition-protected replacement units
-   Charge splitting between banks
-   Lithium-safe charging upgrades

## DIY vs cheap fix vs proper charging repair

DIY

Cheap operator

Proper marine work

Diagnosis

Buy an alternator

Swap the alternator

Voltage and drop tests first

Replacement

Automotive unit

Cheapest fit

Ignition-protected marine unit

Wiring

Not checked

Not checked

Output, ground and sensing tested

Lithium

Not considered

Not considered

DC-DC or smart regulation

Result

Same fault

Fault returns

Charging voltage verified at battery

## Related resources

-   [Why Does My Boat Battery Keep Dying?](/guide/boat-battery-keeps-dying/)

## Sources

-   [Wiring Harness News: SAE J1171 and marine wiring standards](https://wiringharnessnews.com/electrical-standards-for-marine-wiring/)
-   [US Harbors: lithium boat batteries (Jul 2026)](https://www.usharbors.com/2026/07/lithium-boat-batteries-what-boaters-need-to-know-about-making-the-switch/)

Won't start?

Call for a same-day callback and a dockside test.

[(562) 374-7233](tel:+15623747233)

Mon–Sat 7am–6pm · Free estimate within 24 hours

Standards applied

-   SAE J1171 ignition protection
-   33 CFR 183 (USCG)
-   ABYC E-11 (DC systems)
-   ABYC E-13 (lithium)

[Estimate your cost](/tools/marine-electrical-cost-estimator/)

How it works

## How marine alternator repair works

1.  01
    
    ### Describe the symptom
    
    Not charging, slow cranking or clicking. Same-day callback.
    
2.  02
    
    ### Test the circuit
    
    Voltages measured at rest, cranking and running, with drop tests on the cables.
    
3.  03
    
    ### Fixed price
    
    Repair, rebuild or replacement priced in writing.
    
4.  04
    
    ### Run test
    
    Engine run and charging voltage confirmed at the battery.
    

Get marine alternator repair at your slip today

Same-day callback. Written price before any work.

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)

Straight answers

## Marine Alternator Repair questions

### Why isn't my boat battery charging when the engine is running?

Common causes are a slipping or broken belt, a corroded output or ground connection, a blown fuse in the charging circuit, a failed regulator, or a failed alternator. Voltage measurements at the alternator and battery under load pinpoint which.

### Can I use a car alternator on my boat?

Not on a gasoline engine compartment. Marine alternators and starters must be ignition-protected (SAE J1171) so they can't ignite fuel vapor. Automotive units aren't.

### Why does my starter just click?

Usually low battery voltage or high resistance in the starter cables or connections, sometimes a failing solenoid. A voltage-drop test during cranking finds it.

### Will my alternator work with lithium batteries?

Often not safely as-is. Lithium can overload a standard alternator. A DC-DC charger or a regulator with temperature sensing protects it.

### Who does the work, and how do I know they’re qualified?

Long Beach Marine Electric is a free service that connects you with an independent, licensed and insured marine electrician who holds the American Boat & Yacht Council (ABYC) Marine Electrical Certification. Ask your electrician for proof of license and insurance before work starts.

## Related services

[Marine Battery InstallationBatteries keep dying, or the charger won't charge on shore power? Covers battery banks, chargers, switches and parasitic-draw testing.](/marine-battery-installation/) [Lithium Battery ConversionLiFePO4 house banks installed to ABYC E-13, with matched chargers, alternator regulation, DC-DC charging and BMS integration.](/lithium-battery-conversion/) [Boat Electrical RepairDead circuits, flickering panels, intermittent faults. A dockside electrician traces the fault with a meter and a voltage-drop test, then fixes it at your slip.](/boat-electrical-repair/)

Get the charging fault found first

[Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)