MOTEC PDM programming help


Well-Known Member
So this is for the experts.... I am getting ready to order a PDM setup for the car and I am trying to figure out if the PDM will be able to read a negative switch input I have setup for some temp sensors of an oil cooler, trans fan and trans pump. I wired the temp switches to ground cause I was initially going to run standard dash with relays and have them activate the relay on the negative side but cant seem to get an answer if I can have the PDM read the switch input as a ground..

thanks in advance

dzrt performance

Well-Known Member
the Inputs on a Motec PDM (called digital inputs) typically are wired from a switch to the 0V pin on the PDM.

In simple terms, your two wire temp switch, one terminal goes to the OV pin, the other terminal goes to the digital input pin.

you share the single 0v pin with all of your temp switches.

you can also wire a manual over-ride switch in the same fashion and through programming have it turn on the output of your choice. small gauge wire is used as there is virtually no current.

another option is to wire temp sensors to your ECU and have them come across the CAN bus.