I'm still open to other motor and inverter suggestions. I wanted to support OI logic boards.

Right now, the LDU is probably the most powerful option available at a reasonable price. Any of the newer EVs making more power are doing it with multiple motors, and more complex gearboxes.

I think it ...

spiff wrote: ↑Mon Nov 17, 2025 2:09 am Is there some reason the pre-charge contact would continue to stay open?

Is it possible the precharge contactor is welded? Check for continuity with the car off. (be very careful. Checking contactors with a multimeter is how I damn near let the smoke out of... myself)

Ok, I've made a little bit of progress, amid a bunch of other stuff going on. Let's start with the simple, I transposed over the pinout for the inverter module. (in the attached excel file with other Bolt pinouts)

It looks like the inverter is getting:
3 GMLAN Serial Data busses
motor position ...

One other question I have is that now it feels like regen is on, but it gives such a howl when regen is happening. Is this normal?? Take off, cruising and acceleration feel great!! Almost there, but I don't want to take it too far without confirming the sound is okay. Previously, when it felt like ...

I have seen one instance of the rotor shaft stripping out, but I assume that must have been a fluke metallurgical issue, because I have not heard of other reports of that happening. I have seen stories of gears failing.

I do wonder if maybe you should consider keeping the stock gear reduction, and ...

I think HP-wise, you'll have enough, but the durability/strength of the gearing components is a question.

JNHEscher wrote: ↑Tue Nov 04, 2025 11:12 pm Don't quite know yet. This forum is a very different animal, compared to all others I'm on. Ay take me a while to get acclimated to it.

You'll learn it quick. I find this forum to be by far the easiest and nicest to use forum around, once you learn it.

Meant to mention here that I read through all 33 pages of the LDU support thread. Somewhere in there, I think, someone said that somebody out a Tesla LDU in a 19-ton bus and it moved fine. I haven't found said bus yet.



Also, if I remember correctly, Edison Motors used an LDU in their first ...

Wow. 0.5ohm 100W is 14amps peak vs 1.8amps for the one I was using (100W, 30ohm).

What is your HV battery voltage? Not sure how much of an impact the DC-DC on the same curcuit would affect things but I’ll try changing the resistor to what you’re using if it doesn’t.


Wait wait wait, I went ...

Thanks! Good to hear I might have stumbled onto the right track.


Basically you'd want to trace down the function of each and every pin in that 40 pin connector to see where it goes. It's fairly safe to probe around with a multimeter in continuity mode.

Another thing you'll want to do is try to ...

I'm pretty sure this is the resistor I have. I know it was recommended by someone on the forum, but I don't recall where or whom. I would also note that this is only precharging my drive unit, the charger/dc-dc are precharged separately, which was a personal choice most don't do.

EDIT: Wrong ...

Alright so I got my inverter torn just about as far apart as I want to go right now. I've basically taken the approach of "let's see what we can see, and take lots of photos." Here's what I've found:

First, here is the exterior, with the part numbers that I'm looking at. Who knows which numbers are ...

Almost everyone who has offered to take over responsibility, or part of it, has mentioned having a store and wanting to sell things in a store, etc.

But then you're confused why I would think you were interested in being financially compensated for efforts. Even here, you said the same thing ...

Hey all, I'm going to be out in Phoenix AZ next week for Radford Racing School, on Dodge's dime as part of my Charger Daytona EV purchase. I'm going to have some time to kill Friday evening (Nov 7th) and Saturday morning (Nov 8th). I plan to use some of that time visiting junkyards, but if anyone is ...

Thanks, I'll try to take a look this weekend.

Gregski wrote: ↑Tue Oct 28, 2025 1:43 am Freedom Units:

IMG_3007.JPG

That's positively light compared to the fat pig that is my Charger Daytona. Its nearly 6000 lbs! For a coupe!

I have a 2022 Bolt EUV. I also happen to know a bit about SavvyCAN and CAN reverse engineering. So, if you want to go down the CAN rabbit hole, I'm willing to help too. I can give captures of the full traffic on an EUV that is driving down the road.



I was just taking a look at your post on ...

I will, however, make the following commitments to the community:
- I will do my best to get a store set up by the end of the year as an additional source for OI related boards.
- I am actively working on getting the education I need to start helping develop new boards - specifically to work on ...

Got my Bolt inverter yesterday. Probably won't have a chance to take a look inside until Sunday.

It looks very similar to the well documented Chevy Volt Gen2 3.6 charger... and its 7.2 brother. (just different aluminum casting and different HV connector).


Yes, I'm fairly certain that it is exactly the same as the Volt Gen2 7kW charger, with the difference is the upper casing. From my ...

dsp1108 wrote: ↑Wed Oct 22, 2025 3:39 pm Currently considering the transfer of firmware files, calibration, and instructions. Without source code.

Well that's a start! I'd encourage you to consider sharing source code as well to help development, but anything's better than nothing in this area.

dsp1108 wrote: ↑Wed Oct 22, 2025 2:30 pm I completed a project to write software for Tesla 3 and Tesla Plaide inverters.
I'm considering collaboration options on this topic.

Cool! Is this something you'd be willing to share open source?

I just found a good deal on a Bolt inverter, and so I should have that on the bench soon. Not sure I'll have any real idea what I'm doing, but I learn best by figuring it out as I go along, so that's what I'm going to try.

joeflickers wrote: ↑Tue Oct 14, 2025 10:39 am

I don't have any spare Sport phases, sorry.

Base or Sport? And what country are you in?