[DRIVING] 1940 Chevrolet with Tesla Motor

[muehlpower]

Even if it doesn't help now, I have wired my main contactor with its auxiliary contact so that it holds itself. So the only way to switch off is to switch off terminal 15 (ign.), regardless of the settings or the function of the control board.

[P.S.Mangelsdorf]

I have wired my main contactor with its auxiliary contact so that it holds itself.

Do you have a wiring diagram or sketch of that? I've been thinking about how to wire it so that the board still turns it on, but it only turns off with the keyed ignition. Not sure I'd implement, as this really seems like a fluke thing.

[P.S.Mangelsdorf]

For those interested, the failed part on the control board:

[P.S.Mangelsdorf]

Also in (slightly) better and somewhat interesting news, this inverter was easier to remove than my base inverter was. The input current/voltage sensing could easily be removed to get to the main mounting bolts. It does look like it might be an earlier revision than the Base, which is interesting, but I'm not complaining.

Also, it looks like the gate drivers are ok. At least they aren't shorted out.

So I have parts on order, and hopefully they get here quick. Next weekend is the SOC conference, and the IGBTs won't be here until the week following at the earliest, so it looks like August probably for when it'll be back on the road. Maybe a bit earlier if I get really lucky.

I'm thinking about how I can use my old Volt packs to test the charger without the car; I may need to rent/borrow a pickup and give that a shot. I just don't have the home charging infrastructure to test the PWM needed for anything more than 1kW.

[muehlpower]

if your main contactor does not have an auxiliary contact, you can also switch a small relay in parallel.

[P.S.Mangelsdorf]

I have started filming and posting videos about the upgrades to the car, but they are fairly delayed from the actual work. So, jumping back a bit in the timeline, here's the latest video about the LSD and cooling modifications:


In two weeks, a video will release about the suspension fixes and failed rotor, and two weeks after that a video about creating the Franken-drive unit. Hopefully before that point I will have rebuilt the inverter and have a video about that ready to release in another two weeks.

This video ended up longer than I intended, the next two are only 15 minutes each.

[arber333]

I have started filming and posting videos about the upgrades to the car, but they are fairly delayed from the actual work. So, jumping back a bit in the timeline, here's the latest video about the LSD and cooling modifications:

Nice work, thank you for sharing!

Did you consider using the cut orifice to cool the rotor by air. I imagine you could weld a tube onto the previous manifold and add filter and blower. Air would escape the normal route... That way you would have an aircooled rotor instead mass cooled one .

[P.S.Mangelsdorf]

Did you consider using the cut orifice to cool the rotor by air.

Had not thought about that, but it is an interesting idea.

[P.S.Mangelsdorf]

Well I got the new inductor in and soldered to the control board. I haven't really had time to test it with 12V, but plan on doing so and then maybe adding some hot glue to help it stay in place.

The new IGBTs are also enroute to my house, based on the (not very good) tracking from China, they are currently in customs in Hong Kong (I think) and might be here when I get back from State of Charge, or it might be another couple weeks. I haven't started disassembling the stage, I figured I'd wait and do it all at once.

In the meantime, I've started setting up my Bolt testing rig (I'll start that thread soon), and FOCCCI arrived so I need to start on that wiring too.

[P.S.Mangelsdorf]

Well there's good news and bad news.

In the good news, teardown of the inverter phase has largely been smooth. I haven't yet removed the goo and gotten down to the IGBTs, but that's the next step.

In bad news, I ordered the new IGBTs from China over 2 weeks ago. They cleared customs over a week ago, and were handed over the US postal service on Friday. They were apparently out for delivery at 7am yesterday, and then marked as delivered at 10pm. But they were not delivered. So now I've got a complaint in to the USPS and hopefully they can find the damn things so I don't have to go through this again. Exceptionally frustrating.

In other news, my next video is up (suspension modifications and discovering the rotor was stripped) and linked below. I'm working on an edit of my presentation at State of Charge about Drag Week, not sure when that'll go up.

[Aragorn]

can you use the IGBT's from your other DU to repair the better one?

[P.S.Mangelsdorf]

can you use the IGBT's from your other DU to repair the better one?

No, the old DU is a Base and the new is a Sport, so the IGBTs are basically the only part that is not shared by the two units.

[Aragorn]

Ah fair enough, not familiar with the differences, istr with some tesla units they just added more in parallel?

[P.S.Mangelsdorf]

Ah fair enough, not familiar with the differences, istr with some tesla units they just added more in parallel?

Not sure about the other Tesla units but from everything I've seen, especially Fred's teardown here: viewtopic.php?t=1625 the Large was simply a change in the amperage rating of the IGBTs.

[Aragorn]

yeah i'm probably confusing it with something else!

[JDP]

... or SAIC (MG ZS) OBC that Damien hacked lately

I see SAIC (MG ZS) motor+inverter available on eBay and think it would make a great donor for a motorbike project, so I'm searching for info on how to interface to the inverter. I found this post saying it had already been hacked but I don't see MG or SAIC in the model-specific forums.

Is the info out there somewhere??

Thanks in advance,

[P.S.Mangelsdorf]

I found this post saying it had already been hacked but I don't see MG or SAIC in the model-specific forums.

I believe those components are being integrated into the Zombieverter. Check out Damien's videos: https://www.youtube.com/@Evbmw

[P.S.Mangelsdorf]

Well USPS finally found and delivered the new IGBTs, I'm hoping to get to installing them this evening.

[P.S.Mangelsdorf]

My repair of the inverter has slowed to barely a crawl, and I'm hoping some of you have advice.

The only good news is that I've figured out the damaged IGBT(s) are on the low side, the high side has no shorts.

To get access to all of the IGBTs, the PCB they are connected to must be removed. There are two primary pin types attached to this PCB - the control pin of the IGBT, and a pin that I believe connects to the bus bar in some way, but I'm not really sure. The control pins desoldered easily with a 30w soldering iron and spring loaded solder sucker. The other pins I was able to remove the glob of excess solder with a 60w soldering iron, but they remain firmly soldered to the board. I've gotten up to preheating the board with a heat gun and then using a 200w soldering iron, and still making minimal to no progress removing solder. I've tried adding solder, I've tried not adding solder. I've tried adding pressure behind the board and not doing so. I'm at a bit of a loss and really need to get this inverter fixed and back on the road. The image below notes the two pin types.

I'm considering taking this to an electronics repair shop and having them try to do the fix, but I really don't want to do that. Any advice would be appreciated.

[jrbe]

Do you have a non food oven you can put it in to preheat it to say 65°c (or the max sustained temp of the lowest temp component, maybe 85° c? That should help getting the thermal mass temp up so the soldering iron can hopefully do it's job.

I have a fairly cheap smd rework station and I'll use the hot air gun in combination with the soldering iron like you're trying here. I don't think it will be enough to be useful.

You might be able to carefully use an infrared heater too.

There's also the trick of desoldering as much as you can then adding a blob of low temp solder to get it all melting.

A thick desoldering braid might be really helpful.

[P.S.Mangelsdorf]

Do you have a non food oven you can put it in to preheat it to say 65°c (or the max sustained temp of the lowest temp component, maybe 85° c? That should help getting the thermal mass temp up so the soldering iron can hopefully do it's job.

I don't have a non-food oven, but seeing as I'm currently using the kitchen table as a clean workbench for this work, I'm not terribly worried about putting it in my normal oven, so I may try that.

There's also the trick of desoldering as much as you can then adding a blob of low temp solder to get it all melting.

I've had a little bit of luck here but its been unhelpful more times than its helped on the hard pins.

A thick desoldering braid might be really helpful.

I haven't had much success in the past with these, but I might try it out.

[P.S.Mangelsdorf]

The inverter remains unrepaired, but the latest Youtube (from before the inverter failure) is out!

I'm going to try a few more things to fix the inverter myself, and if I fail I'll try local electronics repair shops. I've got another backup plan too, but hoping I won't need it.

Check out the video of better times, when I got the car running again!

[P.S.Mangelsdorf]

Small update; I did finally manage to remove the PCBs, and now I'm wrestling to desolder the busbars and IGBTs. This is slow going but there is some progress happening. My next two weeks have been completely blown up by work and family commitments, but hoping to squeeze in some work on the inverter. I need to get it off my kitchen table, and more importantly I need to get the car running ASAP.

[P.S.Mangelsdorf]

An update and another video not of current progress!

On the update side, I continue to slog through the attempted inverter rebuild. I have finally made some progress removing solder from around the IGBTs but the way some of the pins sit down on a lower level is making final extraction difficult. Once I can finally get down to the individual blown IGBT, I expect reassembly will go MUCH faster than disassembly.

Given my time constraints, I've also reached the point of considering buying another inverter, even if only for parts. Of course I've failed to jump on a few good options on Ebay, but I'm exploring a few others. Really don't want to spend that kind of money, but it's also clear that these inverters were meant to be rebuilt/serviced/repaired at the full inverter or phase level, not the individual IGBT level.

Onto the video, I finally have up my presentation from last month at SOC, enjoy!

[P.S.Mangelsdorf]

I've decided on a change in direction for the repair, as I stare down Drag Week 2024 which is in exactly 3 weeks.

I've purchased some base power stages in need of a gate drive swap from Boxster EV, and will use those to repair my base inverter, which will then go into the car. I'll then move on to the Bolt charger and DC-DC reverse engineering and integration, along with the CCS via FOCCCI integration. I also want to revise some of the cooling system, and would love to actually have functional trunk seals and window tracks.... If I have time to finish the Sport inverter repair, I'll do that and swap it in, but I doubt that will happen. If it does, it's not terrible to swap, compared to how bad it could be. In my car, all I have to do to get clearance is remove the passenger side coilover top bolt, and the suspension drops low enough to allow the cover off and the inverter out. In fact, the drive unit is still in the car right now.

My real world work has been hellaciously busy the past two weeks, so I'm hoping this week will be light enough to allow for some afternoon wrenching, but now that I've actually written that, I'm sure there will be no such opportunity.