Why Simple PDM Keypads are Wiring Game Changers

Changing button functions without needing any physical changes is just one advantage of a PDM and keypad setup as Zac explains in this module taken directly from the PDM Installation and Setup course.

1 of 36 modules from the full PDM Setup and Configuration course.

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WHAT IS A PDM?

A power distribution module (PDM), power management unit (PMU) and power distribution unit (PDU) are all the same thing with different names, much like how variable cam control is called something different by each different car manufacturer.

Over the last few years we’ve seen PDMs become more popular and more affordable which means we’re seeing them pop up in more and more cars running at the grass roots level. These units replace the conventional fuses and relays we need to control and protect the various electrical circuits on our car with solid state electronics to control current flow. This dramatically simplified the wiring installation and can also improve reliability. With a conventional fused circuit, if the current is excessive then the fuse will blow to protect the components and you need to stop and replace the fuse to get going again.

With a PDM the fusing current can be adjusted in software and the unit will simply shut off the circuit if the fusing current is exceeded. The smart part however is that you can then configure the PDM to wait a specific amount of time before retrying the circuit that just failed. You can also set how many times the circuit will retry before failing permanently. This can often be enough to nurse a car with a failing electrical part back to the pits for repair. It’s also possible to log and display the current draw on each circuit so you can see exactly what’s going on with every part of the electrical system.

At this point, a PDM is still going to end up more expensive than using fuses and relays but when weighing up options most enthusiasts overlook the cost involved with mounting and wiring the relays and fuses. When you factor that in, upgrading to a PDM often isn’t going to cost substantially more and by the time you consider the advantages it can start to look pretty attractive.

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