If you don’t already know what it is, the PDM60 is the name of a nicely designed automotive device that allows you to connect up to six electronic devices to your motorcycle (or car or boat) battery and manage the way they come on and off without attaching a huge number of connectors to that battery. It also does away with fuses – for those things hitched up to it. If tobacco companies made 2/3 size cigarettes then the PDM60 would be the size of one of these midget packs. You make three connections to install it – one to the positive battery terminal, a second to the negative terminal – with a sneaky extra cable to a bar of extra earth connections – and the third to an ignition trigger, a connection that only goes live when the ignition is turned on. The idea is that thereafter you can add gadgets to your heart’s delight just by connecting up to the PDM60 using the supply of pozilocks and terminal connectors (for the earth end).

I bought this from Nippy Norman over a year ago and only last weekend built up the determination to attempt to fit it. One thing that deterred me was the lack of any sliver of spare space in the liquid cooled R1200gs. But somehow, by owning it for a year or so, what space there is – under the seats – expanded enough to slide the device and its (in this shot untidy) wiring into place.

Plenty of people have posted their own experiences and reviews of this device – usually glowing. Please look at this for an example of a helpful and modest motorcyclist from Belgium who walks through fitting this. While I think it is a masterpiece of design, I was a little disappointed to discover some limitations.

I fitted a second auxiliary BMW ‘cigarette-type’ socket into a tiny piece of space under the rider seat and connected this to the PDM60. No problem. I will use it to plug in my fantastic Cycle Pump compressor if ever I need to. This will become live a few seconds after the bike has started up, then stay on until the mysterious canbus that runs the BMW’s electrics shuts down about a minute after you take the key out. So far so good. A popular device among motorcycle owners is likely to be a tracking device of some kind. These tend to have a permanent connection to the battery plus a trigger that disarms the device when the ignition is turned on and arms it again when you park it. Rowe Electronics who make the PDM60 gave me some advice, when I asked about how to connect such a device. Unfortunately using the PDM60 does not work for a device that needs a constant top up charge from the battery as this is shut off when the ignition is off. So this had to be wired – at least the positive lead – straight to the battery. Suprise number two was to do with the programming that you can do with this device – and Rowe have recently released a Mac version of this bit of software. You plug in a rather unconventional lead into the PDm and via a dashboard you can change the amps delivered by each circuit or turn off circuits you don’t use. The manual warns ‘don’t do this when the device is attached to a power source’. And they don’t just mean turn the ignition off, they mean disconnect it entirely. I tried without – not understanding – and it was not possible to connect to the unit. I see this as another weakness or limitation. It seems not unlikely that an owner would add devices over time and perhaps want to set up the PDM for them. To do that it seems you have to go to the trouble of disconnecting it from the battery every time you want to make a change. This seems like a bore. Surely it must be possible to design a device that does not need to do this. If I add other electronics then I can see the PDM60 was a worthwhile buy, but if I don’t I am not certain that this nice bit of kit is really worth it for people in my situation.