Advice with choosing type Dynalites


The Dynalite range covers the majority of popular Lucas type dynamos, fitted to the majority of British cars in the 50’s and 60’s. The most common types are C39/C40, C42 and C45. The C39/C40 was generally fitted to most small and medium sized cars whilst the C42 and C45 were generally used on larger saloons and sports cars.

* Use C40 units to replace C39 type units

Dynalites Range


The Dynalite units are based upon original dynamo models therefore to choose the correct Dynalite the original unit needs to be identified. Identifying your existing dynamo is simple, Lucas dynamos are stamped with the model type. (Rust and paint may need to be removed to identify type).

The diagram (below) shows the text found on C40L dynamo.

Dynalite Label
If the dynamo cannot be identified from the stamping, the following table can aid identification from the fitting dimensions.
Dynalites Fitments Dynalites Fitments


The philosophy behind the Dynalite is to create an alternator that is identical to the original dynamo unit in appearance and fitting, requiring no modifications to the vehicles existing mountings or wiring connections.
* Some wiring changes are necessary.

Dynalites Fitments

The Dynalite uses the same output shaft as the original dynamo allowing the original fan and pulley to be used.

* Dynalites MUST run a cooling fan. Original types are acceptable.
* Dynalites operate best using a 2:1 pulley ratio. It is sometimes necessary to use smaller pulleys on large saloons with low revving engines

ALLOY PULLEYS: We offer a range

of lightweight pulleys and uprated fans

suitable for Dynalites.



Power steering and Tacho drive models are available. These are identical in fitting to the original units and can be directly substituted.




What changes need to be made to the wiring?

The Dynalite unlike a dynamo is self regulating, therefore the control box is redundant. There are two ways to rewire the control box for the Dynalite unit. The first is to simply bypass or use the control box as a junction point with two small wiring changes. The second and preferred option is to fit a Powerlite dummy control box.

Dummy Control Boxes:

Identical in fitment and appearance to the original, the dummy unit is pre-wired to aid the necessary changes. Dummy boxes are fitted with an 40A fuse, protecting your electrical system.
We recommend the use of dummy control boxes where applicable.

Dummy Control Boxes


All wiring between the battery and Dynalite should be rated to at least 40Amps (unless stated).







Positive Earth:

Unlike a Dynamo which can be re-polarised, an alternator cannot. Therefore units are available in positive earth. Positive earth units are identical in appearance and fitting to Negative earth units, except for the addition of a relay. (included with all positive earth units).


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