Just looking for some knowledge here….
This question relates if your PSDM is toast.
Have noticed in the q and a a lot of the talk relates to various electrical issues and the owners ability to track down the fault.
I’m a pretty simple guy and got to thinking it might be a whole lot easier just replacing the PSDM with a series of bars that woukd be wired direct and easy to see and understand. One 12v circuit and 1 72 v circuit.
On the 12 v all I have are basically lights, horn turn signal……and the 72v the drive train.
To accomplish that my PSDM has about 50 connections if you include fused.
Anybody tried direct connections vs PSDM.
Sure, it could be bypassed, but it depends on what factory features you are willing to abandon. There is still much magic that happens inside that little black box.
One 12v circuit and 1 72 v circuit.
One unswitched 12v (always hot when Bat is switched on), Then a switched(with KeyON) 12v, as well as some B+ 72V stuff.
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Obviously the KeySwich does it’s thing inside the black box. A board mounted relay wakes up the dash systems, but also wakes up the Switched side of the DC Converter.
The Handbrake loop is pretty much an afterthought and is already jumped around the PSDM, so no real issue here. It’ll still need something to throw a beep if left unset and KeyOFF.
The muxing of the 4 corner lights goes on in there. Tail lights are easy, but your brake lights are separated from your turn signals yet they use the same filament and needs to figure out how to send the flashy thing at the same time, BUT ALSO not send the flashy signal to the front turn lights without sending the brake signal. Yes, that can all be bypassed and re-generated with a few aftermarket components.
The Direction Selection also goes through here, which is also not really needed, but when reverse selected it sounds a beeper and provides an output for backup lights. Easy enough.
What is going to be really tough is the Serial Data from the controller to the Dash panel passes through here. I haven’t tested to see if it can be jumped, but I have yet to find any info on is how the data is generated for the SOC display. The shunt is on the right side of the PSDM and a key component to that system.
The details of the PSDM were so protected that all the chip info was wiped off the chips before they ran the conformal coating over the board.
thanks for the great info plus love to picture of the psdm insides…very enlightening