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Upgrading from a struggling dynamo has never been easier and offers numerous benefits. Take charge with our fitting guide to how to install a dynamo alternator.

Classic Fords reliant on dynamos to run their electrical systems (most models up until the late ’60s/early ’70s) suffer from a general lack of available capacity. This is especially true when all the major electrical components are required at the same time, such as wipers, heater and headlights. Auxiliary items such as heated rear screens or radios only compound their inadequacies. 

To cope with the extra load, alternator conversions have been around for decades and were available as optional extras on some vehicles. However, Powerlite’s dynamo alternator – the Dynalite – is an alternator that looks like a dynamo, giving you the best of both worlds. 

Even better, it’s a worthy upgrade that can be fitted easily in around an hour using basic tools. Here’s how to do it.

how to install a dynamo alternator

Disconnect the battery earth lead. Remove the coil HT lead if the coil’s strapped to the dynamo, as on many British classics. Label the LT leads to the coil if necessary and disconnect them.

Undo the three mounting bolts and their nuts. Ratchet spanners or a small socket set are best used because space is tight. Avoid damaging the radiator core by placing a sheet of cardboard in front of it.

Remove the fan belt from the dynamo pulley. Remove the dynamo and coil assembly from the engine bay.

Undo the coil mounting bracket nuts and remove it from the dynamo.

The old dynamo pulley is reused on the Dynalite. To remove it, undo the two long bolts securing the backplate to the frontplate. A bench-mounted vice makes the job easier, as does a suitably large screwdriver.

Extract the main armature body and pulley assembly. Mount them in a vice.

Undo the pulley nut.

We used a small hub-type puller to remove the pulley. Alternatively, try levering it off using a large screwdriver. If unsuccessful, then a series of gentle taps with a hammer should work —
avoid chipping the pulley rim. 

The pulley and its fan blades slide off when aligned with the Woodruff key.

After a quick clean up and fresh coat of paint, the pulley and its fan blade assembly were fitted to the Dynalite.

With the pulley held firm, its nut can be tightened.

The Dynalite is then refitted with the coil mounting bracket and coil assembly, and fitted to the engine.

Tension the fan belt and tighten three mounting nuts and bolts.

The Dynalite, just like an alternator, makes the old control box obsolete. Powerlite’s neat modified control box is an easy fit and looks original, plus it allows the ignition warning light to function.

The replacement control box is available with Lucar or screw terminals. We chose the screw terminal version, as we want to connect auxiliary wires easily at a later date. 

Disconnect its wires and undo the screws mounting the control box to the bodywork.

Both screw and Lucar versions are a straight fit with one minor alteration…

how to install a dynamo alternator

…the terminal D wire (usually brown/yellow or yellow) is now joined to terminal D. This feeds the warning light. 

how to install a dynamo alternator

The wiring at the Dynalite end remains the same. The large and small terminals connect as they did to the old dynamo. 

We chose to run new 40 amp cables from the battery and to the Dynalite (D&A control box terminals). This is recommended if the old wires are frayed or damaged in any way. 

We ran the two cables using the routes of the originals and then wrapped them in loom tape.

Having double-checked the wiring, reconnect the battery and turn on the ignition. Check for warning light illumination on the dash. Then start the engine and check the volts being fed back to the battery — 13-14 volts is ideal. 

how to install a dynamo alternator

Another test with main beam, heater and indicators on showed less than 10 amps was being drawn, leaving a whopping extra 30 amps of capacity to call on if required.

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