PDM output Increase/expansion

Hi all

Been in the process of a ground up build for the last year and a bit, and its coming to wiring. the old harness (1985) is toast.

Since learning about PDM's, the relay and fuse system seems archaic, and not something i want to pursue - however it is not a track car, or a bare bones street car, it,s a fully fledged touring 4wd setup. somewhat unfortunately that comes with a lot of 12v accessories.

There is not much on the motor to run from the PDM, being diesel, no injectors, coils, plugs.. - aside from starter, alt & supplying power to the motor harness/ecu - its almost a standalone harness.

i am looking at somewhere around ~38 outputs required. I've grouped together what i can (i think). this spits out 3 ecumaster 16's, or a motech 30 and 15 - 48 and 45 outputs respectively, and around the $5500 mark ea. a lot for a few extra outputs

My question is, is there anyway to split a single output in to many, low current options? my example is multiple small, low draw LED strip lighting. obviously i don't want to group them to a single output and have the entire car light up.

the only way i can think of doing this, is to have the output run to multiple switches, and each of those switches directly feeds each light power.

I know this is not the standard way (switch deals with low current, signals relay to provide actual current to device) but i was wondering if i used switches capable of handling a small/decent amount of current, and only used it when dealing with multiple small draw devices (led light strips) if this would be acceptable way to do it.

the 'fuse' would still pop i believe, if any short occurs so as long as the switch can handle the current i cant see an issue?

window motors also eat a lot of outputs, being full bridges :( might delete the rear two, save 4 outputs

Hopefully both the image's are legible - may have to upload again if not

excuse the crappy drawing.

thanks for your time, any suggestions welcome

The switch option can be done, the MoTeC PDM's do not have Half/Full Bridge outputs for controlling the windows.

Ah good to know thanks Stephen. I may do the switch idea, but it only gains me a few outputs - not enough to save an entire pdm. more options down the track i suppose.

thanks

Honestly 2-3 PDMs in a vehicle like that is common, so you're not off in the weeds.

The switch idea could work. When it comes to low draw LEDs, perhaps consider having more on than needed in fewer groups where it makes sense.

If you're talking high draw LED exterior lights, then by all means separate them so you can best manage amp draw.

Thanks Mike! good to know im not doing anything too weird!

They're only low output lights id consider putting on the switches.

appreciate your reply

You're welcome!

the Blink Keybox canopen Slave Output Expander is what i recommend to anyone needing a few more outputs that are less than 10A per circuit.

I've made them work with ecumaster pmu and c series dashes