Powerdynamo, integration of PD System into existing grid

Powerdynamo brings new ignition & light
to your vintage motorcycle



Technical Help



How will a Powerdynamo System be integrated into the existing electric grid of the motorcycle ?

this refers to integration of the lighting voltage production side of our systems. The ignition side is (save for the blue cut off wire) integrated in itself.

The short answer is: Integration happens at the battery (or, should you opt not to use one, at the wires where the battery was connected). Between battery plus and the red (plus) wire of the new regulator you should install a fuse (as indicated in our instructions).

All Powerdynamo Systems arrive with a wiring diagram and instructions which contain a verbal description of the wiring.

This however only gives the wiring between the individual Powerdynamo components and ends at the battery and main switch.

The motorcycle has (normally) its own electric grid and you need to integrate the Powerdynamo grid into it. The matter gets a little difficult when (as in many older bikes) the stock gris is a dual voltage grid, carrying both AC and DC (AC for the power consuming headlight and DC for battery charging, flasher units, horn. For this see KB entry AC/DC integration

The ignition side of the Powerdynamo System is selfcontained, connects its elements with the plugs and terminals provided and the only integration of this part with the older bike structure is the connection of the blue wire to the main switch. This is explained in the instructions.

Integration of the DC lighting voltage supply side of the PD system is generally speaking done by connecting the brown (in 6V systems white) wire of the new Powerdynamo DC rectifier/regulator to good (negative!) ground (best the point the battery was grounded) and the red wire to plus of the battery.


Any battery containing electrical system of a motorcycle would have a wire that runs from the live pole of the battery to the main switch. Let us call this wire for the purpose of this paper feed wire. This wire has to be maintained. Without you will not have any lighting or horn function.

We know of many customers who in the frenzy of installing the new PD system cut of a lot of wires, including the feed wire. As a result they get the bikes ignition running, but do not have any lights or other electric functions. So take care to identify the feed wire from start and keep it!

If you want to drive without battery than you connect the red output wire of the Powerdynamo DC regulator directly to the feed wire. Please know that without battery the relay which may have been delivered by us in systems replacing stock dynamo systems may not work and ignition cut off has to be done via a kill switch.
A very basic wiring diagram of a motorcycle with the PD system would look something like this: