2005 GEM Lithium Install / 12v power source issues

I recently bought a plug and play a package from Inwo, It installed nicely and my speed increased from 25 to 30 MPH, I was hoping to get 35MPH but it seems I have a T3 controller and I need a T4 controller that can be reprogrammed while my T3 may not be. That is something I am working with Inwo as maybe the T3 can be modified, he is not sure but we may try something this winter. Any anyone has a T4 that they are not using I would be interested in purchasing it.

The reason for my post is I bought from Inwo the external display that would show the batteries condition. I am using a small plastic box to house the display and while I was at it I thought I would add some 12v and 5v USB ports to the box and a GPS speedo. The display works but does shut down after about 30 seconds and the momentary switch does not do anything.

I had trouble finding a good 12v power source, I hooked it up to one but I have a big light bar on that circuit and I really do not think that is going to work long term. I thought I found a solution with the fuse block on the lower dash but it is very erratic, sometimes it works sometimes it doesn’t I need to play with it some more, If you have a suggestion for a 12v source I am all ears.

Also I have tried 2 converters to get the 5v for the GPS display, which are failing. I have 13.39V and when I power it up both style converters I have tried they have immediately started to smoke and shorted out between the 12/20v ± and between the 5v ± I tested them before powering up and no shorts. I tested the GPS cable and it is not shorted. I have no idea on why this is doing this. I have used one of this style converters to convert Dewalt 20v batteries to 12V and it worked great. But 5v nooo way!! Andy thoughts?

You have a 2005 and cannot find a 12v power source?
What are you currently using? (where are your wires hooked?

On the left side of the PSDM you will find a row of accessory connection points. You will need to remove the upper and lower dash panel to get proper access to the front of the PSDM. Reminder → 12VDC accessories use Chassis Gnd for -12v.

Note that A and B are 72v.

What are the Specs on your little 5v converters?

Yes, look for grounding issues. Isolated supplies?
The JK lcd is isolated, I think, and can work from the 12v system. Not 100% sure. Nobody has reported issues. The new ones are on a timer in bms, I’ve been told.

Iirc, that empty F11 on the psdm was actually for a strobe / light bar for a parking enforcement option package.

These are the converters I tried



I hooked them up to a 12v source with no load but as soon as I applied power they shorted out. I was using chassis ground. The connection for the 12v is the same one as my light bar that works, I just do not turn the lightbar on to prevent a heavy load. I need to look at my ground setup within the plastic box again to see if I screwed up, maybe there is an internal short I am missing. The source of that ground is a chassis ground so it must be in the plastic box.

When I test the connection points on the left side of the PSDM sometimes I get voltage sometimes not, or maybe it is just me being stupid and not having the key on.

Unfortunately I will be out of state…again, our daughter with new twin girls has raised the white flag, we are off to assist for a week.

I might have missed it, but I don’t see specifically that they are isolated.
As they are 4 wire you would expect it to be. Easy to test. Look for continuity between in and out.

I have tested converters like that before, and yes, if the grounding is not proper, the converter can quickly destroy itself. I was testing the failure modes relating to bad grounding and had a capacitor pop straight out the case on the workbench in front of me.
Measure twice - draw a schematic for your grounding pathways and ensure the converter is installed in the proper electrical location! If the 5V side is isolated on the converter and not on the control board - then you probably need a different converter.
Post a schematic maybe and we can review / suggest more helpful things.
Good luck!

Well I solved my problem, it appears some less than smart person (me) connected my converters polarity in reverse. The info AssyRequired was a great help on the fuse panels connectors and it allowed me to get the display box and the 5v GPS made working properly.

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