openinverter forum

this is a companion thread to the Junkyard Report: 2009 Toyota Highlander AWD I don't mean to litter the forum with nonsense, and I hope you will see purpose in it being its own stand alone thread, rather than lumping it into the other one as I hope we can point out some of the similarities and differences between these two animals

what drew me to this vehicle was it's lighter/flimzier rear motor subframe, or so it seemed, also this was the only RX400h in all of the Pick N Pull junkyards in the United States so I had to take advantage

Shameless Self Promotion Time - SSPT

Yes I hope to feature whatever I yank from this car in my TOYOTA's Hybrid Synergy Drive System Cross Pollination - Say What? YouTube video series as I hope it will complete the full offering of:

• Front Motor Front Wheel Drive - FMFWD

• Front Motor Rear Wheel Drive - FMRWD

• Front Motor All Wheel Drive - FMAWD

• Rear Motor Rear Wheel Drive - RMRWD

... and yes I have no life, there I said it

(if you could be so kind and let me know if you enjoy these Junkyard Reports I would really appreciate it, otherwise I will hoard all this knowledge myself, hee hee)

let me just rate pulling the inverter out of this vehicle as the most difficult strip I have ever done did, if I'm being honest I attempted to yank the one out of that 2009 Toyota Highlander but gave up!

Fun Level: -400

here is a fun little progress timeline of the front of the car during the three hours it took from start to finish


got the hood [pronounced: "bonnet"] off of the car cause some dingleberry deleted the prop stick, and the front bumper came off

modern cars have that silly windshield cowl under the windshield wipers which I swear covers a 3rd of the engine bay, so that had to go, as did the rad

on these older style inverters the whole lid has to come off in order to undue the three bolts for each of the three HV motor cables

and the inverter is out, but we were far from finished as I decided to go after the resolver cables next, and of course any pig tails

so this is what we were after, and I needed another inverter like another hole in my head

and here's what it looks like inside, all the connections are hard wired


I decided to intelligently remove/unplug all the external connections such as this Air Conditioning high voltage cable (don't ask me why)

and this is the business end of the inverter

THREE motors connect back here (if you want to get all their bolts out, bring a magnet on a stick, trust me)

it took me a while to finger out how to remove the back bracket of this inverter


It was held on in the back, and these two bolts were not it!

and approximately 90 joyous minutes later she was out, but we weren't done yet


Note: all the external connections have been carefully and properly unplugged and removed

I went after the MG1 and MG2 resolver cables next - you know The Greg he just has to have his OEM harnesseseses

I kept picking her to the bone and got the Sync Serial harness as well or at least a good length of it

three hours later, I was dying of thirst, but we had ourselves yet another Toyota(ish) inverter

... did I mention this monster is heavy ?

The goal here is to see if we can take a complete rear motor / subframe out of one of these animals and bolt it up or graft it in to some OEM rear engined vehicle such as the VW Beatle or the Corvair. Since the 2009 Toyota Highlander AWD seems too wide

WHAT WE KNOW

The 2006–2008 Lexus RX400h has a rear track width of 61.2 inches (1,550 mm). BINGO !!!

The rear track width of the modern Volkswagen Beetle (A5 generation, 2011–2019) is approximately 61.1 inches (1,552 mm).

as much as I would love to convert a classic Beetle or Fastback, I must follow the path of least resistance


2012-2019 Volkswagen Beetle Rear Subframe Crossmember / 61k / VB004

and just so you don't think I'm crazy I am not the first one to entertain this type of EV Conversion, here is the man himself, though he is using the 4" wider rear track Lexus RX450h subframe

My vote… do a Corvair!!!

Ghia66 wrote: ↑Sun Feb 15, 2026 6:14 pm My vote… do a Corvair!!!

looks like GM already beat me to it

So today I decided to go do some "modern" VW Beetle recon in the junkyard, and tell you what a complete fool I am


What's wrong with this picture ?

That's right, the engine is in the FRONT ? Did I know that, um no, yes I am a complete idiot! What next, four door Porsches?

so I am aborting the modern Beetle conversion and may try to convert a proper rear air cooled engine classic one, if I find one at the right price or for FREE, I am also tying to convince my Bestie to buy one and partner up with me on the conversion where he ends up keeping the car

So with my tail tucked in between my legs I decided to revisit this RX400h and see if I can pull some of them MGR motor and inverter cables and maybe battery cables as well

here is part of the octopus pulled from the front of the vehicle and out from under, of note is that yellow section which runs to the electric power steering rack



and here is the battery pack cable liberated

Hidden in the back of the vehicle is what I believe is the 300 volt air cooled DC-DC Converter part number G9250-48011

I did not end up buying the DC-DC converter I just took it out for a photo shoot

I was super happy to be able to extract the home run MGR rear motor cobles that run the length of the car from the trible inverter housing all the way to the rear diff without having to drop the motor

so this is what I ended up buying for a total of $67 dollars, the guy charged me like $20 bucks each for what he called miscellaneous Electrical cables, don't ask me about Pick N Pull math

so Motor Cable, Battery Pack cable, Motor Temp sensor harness, Resolver harness (green)

Hey Greg, do you know if there has been any work done on controlling that DCDC converter? The leas coolant pipes the better is my thinking…

Scrappyjoe wrote: ↑Mon Feb 16, 2026 8:06 pm Hey Greg, do you know if there has been any work done on controlling that DCDC converter? The leas coolant pipes the better is my thinking…

honestly I don't know, but if that 300v spec holds true I would guess it would be highly unlikely as that is about 100 volts too low for what we run our 400v EV Conversions on

if you are not a fan of liquid cooled DC-DC converters or separate units for that matter, please consider any of the following options, most definitely not in order:

the air cooled Gen1 Chevy Volt DC-DC converter

The Two In One Mitsubishi Outlander onboard battery charger with a built in DC-DC converter

it is also common for the Inverters themselves to server as DC-DC converters, think Gen 2 Prius (and maybe Gen 3 Prius as well)

and finally keep your eyes out for this 2017-22 Prius Prime air cooled onboard battery charger / dc-dc converter soon to be reverse engineered

Quick note on this:

Hidden in the back of the vehicle is what I believe is the 300 volt air cooled DC-DC Converter part number G9250-48011

This unit is generally sold on eBay and the like as either a 'power steering control module' or 'power steering convertor assembly'. So I think it's a step-down converter that does not put out 12v.

Googling the RX400h electric power steering specifications, I found one document here https://techinfo.toyota.com/techInfoPor ... rx400h.pdf which states the EPS is rated at 42v.

Another Toyota doc says 46v https://techinfo.toyota.com/techInfoPor ... 0h_erg.pdf, but most references are for 42v

The 42v comes out of the yellow cables.

This link https://www.mri-auto-diagnostics.com/c1 ... us-rx400h/ details guidelines for debugging inoperative power steering on an RX400h. It includes two handy wiring diagrams.
These are the diagnostic instructions:

Testing:
- Check for 42 volts on the White wire at the Power Steering ECU connector (P47 – 1).
- If there is voltage, the converter is good. Suspect Power Steering ECU.
- If there is no voltage, disconnect Power Steering ECU connector, start the car, and apply 12V to Yellow/Black wire (P41 – 11). This is 12 volts coming from the Power Steering ECU to tell the Power Steering Converter to output the 42 volts. 42V should now appear at the White wire (P47 – 1).
- If there is no voltage, verify that between the Red wire and the Blue wire at the Power Steering Converter there is at least 288V when the ready light is on. Check fuse if there is no voltage. Fuse is replaced together with the Main Relay.
- If there is voltage, check Power Steering ECU power and grounds. If OK, replace Power Steering ECU.
- After replacing old PSU Module with the new one, it will need to be calibrated (Torque Sensor), otherwise, it won’t work.

This suggests to me that if you (1) ground the convertor (2) apply HV to the HV input cables and (3) apply 12v to the yellow/black wire, you should see 42V coming out the other end.

No idea on rated current, can't find that documented anywhere. Can't find a fuse either. Apparently it's fused on the inside of the pack.

just wanted to share where the short lived Lexus RX400h falls on the TOYOTA's Hybrid Synergy Drive System - THSDS


for a three year run (2006, 2007, and 2008), Pick N Pulls sure are littered with them, hmmmm ? makes you wonder why

Gregski wrote: ↑Mon Feb 16, 2026 8:50 pm honestly I don't know, but if that 300v spec holds true I would guess it would be highly unlikely as that is about 100 volts too low for what we run our 400v EV Conversions on

if you are not a fan of liquid cooled DC-DC converters or separate units for that matter, please consider any of the following options, most definitely not in order:

the air cooled Gen1 Chevy Volt DC-DC converter

The Two In One Mitsubishi Outlander onboard battery charger with a built in DC-DC converter

it is also common for the Inverters themselves to server as DC-DC converters, think Gen 2 Prius (and maybe Gen 3 Prius as well)

and finally keep your eyes out for this 2017-22 Prius Prime air cooled onboard battery charger / dc-dc converter soon to be reverse engineered


IMG_5439.JPG

Hey Greg, how does this compare in size to the Outlander rig?

Do you know what the kWh charging rate is?

Looks real tasty!!!