iMIEV – Spinning the Motor & Wheels

by Ben N on July 22, 2014

Last week, I had made a date with my friend Tom G (who you might remember from the AC Dodge Neon project) to come out to my house and show me how to use a variable frequency drive. Tom has lots of experience working with AC motors and owns a few salvaged drives.

I had already started work disassembling the Mitsubishi i-MIEV’s motor controller. Getting the top cover off, it really didn’t look bad at all inside. Next, I started removing the electric connections and cooling lines to pull the entire controller out. That’s about when Tom showed up. He worked on getting the corroded battery cables out of the controller while I went under the car to remove the cooling lines. Electric car coolant IS delicious, as it sprays all over the bottom of the car, but at least I did manage to get more of it in the bucket than in my mouth…. Ick. Still better than when I drained the gas tank on the Geo Metro.

DSC_2384Once everything was disconnected from the controller, we pulled the entire box out and set it to the side. We now had a good view of the motor and differential and access to the three motor cables. Tom set up the VFD and we plugged it into my 240VAC electric outlet that I had installed for my welder. On the other end of the VFD we connected the output wires to the cables going to the motor. I already jacked the car into the air and then lowered it onto jackstands. The iMIEV is rear-engine/real-wheel drive. With the wheels up in the air, and the temporary motor controller hooked up, in theory, we should be able to make the wheels spin.DSC_2379The gear selector cable had already been removed from the transmission, so I could just reach down there and manually put the car into park, reverse, neutral, or drive. I popped the car into gear, and we were ready to give it a shot.

Tom turned on the controller and activated the run mode. Odd musical notes started playing from the car’s motor. I know that this has to do with electronic switching happened at a frequency within the range of human hearing, but it’s still weird to HEAR a motor playing techno-bagpipe music. A moment later, the right rear wheel started to slowly spin.

We played with the VFD for a little bit. The left wheel was dragging a bit. I think there is some rust on the brake or bearing, it didn’t seem to spin as freely as the right wheel. DSC_2387Turning it by hand would briefly make both tires rotate. Tom said that the motor was drawing more current than he expected and that we should have been able spin the motor faster than that as well.

His brief diagnosis? The motor worked, but was NOT in healthy tip-top shape.

So what’s the next step? Perhaps removing the motor and transmission. Both parts are pretty easy to get to under the car. The transmission would pop right out if I could figure out how to remove the drive-shafts. I haven’t worked on a car before that has the style of suspension that the iMIEV has in back. I’m not quite sure How I would remove the wheel assemblies to make room to pull the drive axles so I could drop the transmission. Oh well, that’s for another day anyways.

DSC_2388Returning my attention to the car’s original motor controller, I flipped it over to access the bottom cover. The controller is a big aluminum box with liquid cooling and holes for the battery and motor cables. It’s also multi-dimentional – two layers of electronics in one box. I pulled the dozen or so 8mm hex bolts from the bottom cover and then pried it off. *Sigh* I saw about what I expected too. Sea water had gotten inside and then sunk to the lowest point completely corroding and destroying all the electronics inside. I poured out what looked like sand. I guess it sort of was. Combine oxygen in saltwater with aluminum and some electronics and you get aluminum oxide and silica.

So, the controller is toast, but on the upside, the IGBT modules on TOP of the unit look just fine. Perhaps they could be pulled and used as part of a DIY Open Source AC controller?

Again, this project has been an interesting combination of disappointment at the damage and fun of taking it apart. It’s not every day that I get to take apart an otherwise brand-new electric car!

Til next time, stay charged up!



Auto Parts Road Trip

by Ben N on July 21, 2014

This weekend, I found myself having a bit of fun building interesting Plug-in Vehicle projects.

Recently, I’ve been chipping away on my diesel engine, updating the old glow plugs to new ones. At the heart of my DIY Hybrid Pickup project is a diesel engine, in this case one that I got from a 1976 Mercedes 240D. My next big hurdle is trying to figure out how to mate it up with a Chevy S-10 manual transmission. I have little experience working on transmissions, and that has been slowing the project down. If only I had the manual transmission that would have gone with that particular engine, I would have something to work from. Alas, there’s not that many 40-year-old manual diesel transmissions kicking around. However, I was able to locate one through the web that was at a salvage yard about two-hours-drive away.

IMG_0237On Friday, I had a job that would be finished by a little after 1 PM. After that, I hit the road to head north from the Milwaukee area, past Oshkosh (the Osh-Vegas campground was packed!) past the (other) EAA and up onto the roads less ventured. It’s always interesting to see what’s out there once you are off the main roads. Wisconsin seems to have a strange affection for “roadside oddities”, and this trip didn’t disappoint. I saw a full-scale Brontosaurus and T-Rex at a closed-down golf-course. On the way home, a giant fiberglass pig advertised a local meat-cutter.

IMG_0240I finally arrived at Schmidt’s New London Auto Salvage, a lively junkyard with plenty of crashed cars on display up front at huge discount prices and a big yard out back. I had called ahead to make sure they would have the transmission. Looked like it was a busy day there. As I pulled in, one guy was loading a pair of engines into the back of a pickup. I headed in to where the sign said “Office” and inquired about the transmission. The owner was busy on the phone, but got to helping me right away as he was finished. I was glad to see the transmission was already in the front. I was helped out by “Junior” and another employee, and it didn’t take long before I was explaining what it was I really wanted to do. I told them about the concept of the diesel engine and forklift motor to build a hybrid truck. Right away, the one guy’s eyes lit up, and said “Hey, I know what you need. Come over here.” I followed him into the side yard, expecting to see a half torn-apart forklift, and instead saw a silvery flat rectangle – a battery pack. “It’s from a Ford Escape”, my escort announced. Sure enough, “Ford Motor Company” was emblazoned across the top of the case and “300V” was listed on the small warning sticker.

I had already spent two hours to drive to the middle of nowhere to get an old manual transmission for a diesel, and on top of it, they JUST HAPPEN to have a hybrid battery pack kicking around. Not only that, they also had a Prius inverter (which I really had no need for) and I had JUST MISSED three Prius battery packs.

I paid for the transmission and battery and the guys strapped down the battery pack to a mini pallet and loaded it in the back of the truck. “Come back here and see us when you finish that hybrid truck project” was the parting words from the salvage yard.

IMG_0244On the trip home, I rolled 250,000 miles on the truck’s odometer. It’s started leaking oil lately and about time for a new engine. Maybe now is the right time for a hybrid upgrade anyways.

Although the trip home was otherwise uneventful, I did still have to figure out how to get the battery pack out of the truck. It weighs about 200 pounds, and is an awkward shape. I didn’t have a forklift, but I did have a plastic cart that was about the right height.  IMG_0242 I slid the battery off the tailgate and onto the janky  A/V cart. Carefully,  I rolled it into the garage, trying to keep it from tipping while going over not just the bumps, but also the cracks in the concrete big enough to lose a wheel in. At this point, the cart was starting to lean, and the one crack in it was looking larger than usual. Fortunately, I made it over to my chain hoist.

Conveniently located on the side of the battery pack were a pair of blue straps tucked away and held in place with a bolt. I unthreaded the bolt and pulled out the strap, revealing six inches of strap that I could hook a chain to. A few minutes later, I was relieved to have the weight of the battery hanging from the ceiling, instead of on a junk cart, although it was now suspended over the diesel engine and my electric motorcycle. Still, I felt like I had come a long way since pulling the engine out of the Geo Metro with little more than a clothesline and will-power.

DSC_2369A 300V battery pack has some possibilities. For one thing, I have a dead Mitsubishi iMIEV sitting in the other half of my garage. The deadest part was the battery pack, which swallowed more than its share of Atlantic Ocean during SuperStorm Sandy. Although a Ford Escape Hybrid battery pack is only a fraction the capacity of the iMIEV battery, it’s still 300V and has some possibility of being able to power the car, even if only for a mile or so. Unfortunately the water damage ruined all the circuit boards in the car, so it’s going to be a lot more work than simply replacing the battery if I wanted to run it as a stock electric car. The other fun possibility for the battery is that it make work well for an electric motorcycle battery pack. 300V at 5AH works out to 60V at 25AH. Not a giant battery pack, but only higher voltage and lighter weight than my old four Optima YellowTops.

Speaking of the Mitsubishi, last week, I called up my buddy, Tom, to see if he could give me a hand testing the motor. (You probably remember him from the AC Dodge Neon project.) We figured that we could see if the motor at least works or not by trying to drive it with a known good motor controller. An industrial AC variable frequency drive should work fine running off the 240V outlet I use for my welder. Tom is supposed to come out tomorrow to lend me a hand with this, so I thought I’d get started my jacking up the car and getting at the motor and controller.

The controller is pretty easy to identify. It’s right on top of the motor and has 5 high-voltage orange cables, two for the battery and three for the three phases of the AC power. I pulled out all the bolts holding the cover of the controller on. No worries here about electric shock, the battery was completely dead and removed months ago. (I still have to figure out where to go to recycle the lithium cells!) Once the cover was off, I got a look inside. There was corrosion on the battery cables, but the motor connection cables looked good and clean, as did all the copper and circuit boards in the controller. For all I know, the controller works fine.

I disconnected the motor cables from the controller, figuring that we can connect our test controller straight to those for a simple connection. So that’s it for my weekend. Now, I’m waiting for Tom to stop out and see if we can figure out that motor. It feels good to finally be working on some projects again!

Til next time, stay charged up!




Glow Plugs, Part 2

by Ben N on July 16, 2014

When last I left you, I had an engine with the glow plugs removed, and the remaining holes gunked full of carbon. Everything I’ve read so far strongly suggests reaming out the carbon when replacing glow plugs.

I had looked online and found that a specialty reamer tool for glow-plug holes were over $50! I just want to clean out these holes, not clean out my pockets at the same time!

The next day, I was over at the auto parts store (for something completely unrelated) and saw that they had a set of five screw extractors for $14. I don’t already have any screw extractors and thought to myself “What are the odds that one of these fits the 240D glow-plug holes?”. So, I spent the money and excitedly hurried home to try it out.

DSC_2219Sure enough, I took some measurements of an old glow plug, a new glow plug, and the two larger screw extractors of the five in the set. It looked the the largest (#5) was just a hair bigger diameter than the old style glow-plug – just perfect for reaming out the hole.

The first hole reamed-out just fine. I was able to put the #5 screw extractor straight in the glow-plug hole. I easily turned it by hand, and saw black flecks of carbon dust get pulled out. The next one was a little more difficult, and I didn’t have a good handle on the reamer. I did notice that it was the same size square connection as a medium socket set. So, I got out a male hex socket (which happened to be 10 mm) and then put a regular 10mm socket onto that, and lastly connected a socket wrench. I now had a reamer connected to a nice big socket wrench handle and I could easily wrench left while applying a little pressure to push the reamer into the hole. Who needs to spend $50 to do that?

I reamed out the other two holes and then finished the job by putting a long, skinny air nozzle into each hole, and applying compressed air. Blasts of black carbon dust shot out like tiny mortar rounds, leaving only a clean aperture behind.

I was now extremely confident that the glow plug holes were in prime condition for the new plugs.

DSC_2223I applied a little bit of anti-seize to the threads of one of the new glow-plugs and started threading it in by hand. Oddly, the plug stopped turning before it was all the way to the engine block. Confused, I once again compared the old and the new and noticed that the threads on the new plugs did NOT extend as far as they did on the old. It looked like the new plugs were NOT designed to screw all the way in to the engine block. They would instead extend out from it just a bit.

After running all four of the spark-plugs in, I set to wiring them up. This was pretty darn easy. All I did was put a short, heavy wire from each spark plug to the next. I found my purple-and-white wire that went to the original glow-plug relay connection, and hooked that up as well, even though it wasn’t going to a switch or battery.

DSC_2227After finishing installing the new glow plugs, I reinstalled the fuel hard-lines. I love the way these look. Kinda steam-punk, only genuine awesomeness instead of faux-Victorian imaginary!

Before starting this all, I also tested one of the new glow plugs to see how much current it would draw. I simply connected it to a known good 12V battery and completed the circuit through my multimeter, set to the DC Amps setting. The meter read about eight and a half. I figure that if each plug draws up to ten amps, I’m going to need a 40-amp fuse and relay to run the glow plugs.

So there you have it, fancy new pencil-style parallel-wired glow-plugs in a four cylinder engine from a 1976 Mercedes 240D. This “Super-Truck” project has been a slow one, but it really feels good to be chipping away at it and learning as I go.

Til next time, stay charged up!



240D Glow Plug removal and inspection

by admin on July 15, 2014

The “Super-Truck” project is something that’s been in the back of my mind for a while. The whole idea is to build a plug-in hybrid pickup, which could run off diesel, battery electricity, and biofuels. Imagine if a Chevy Volt not only ran on bio-fuel, but could also haul firewood and tow a trailer!

Too bad I know next to nothing about diesels.

So, I’ve been slowly learning as I can, reading books and watching online instructional videos, and chipping away at the project. I have a diesel engine out of a Mercedes 240D sitting in my garage. I’ve already test-run it and replaced the water pump. It’s still using the old-style glow plugs. While I’m waiting to eventually get on the same schedule as my diesel-mechanic buddy to perform some REAL work on this project, I thought I would give a shot at upgrading the glow-plugs to the modern style.

I ordered a set of four “pencil” glow plugs from Mercedes Source. My order also included a nice little book showing exactly how to upgrade from the old glow-plugs to the new. So, the other day, I set to replacing the plugs.

To start with, the glow plugs are actually rather difficult to get at with the hard fuel lines between the injection pump and the cylinders getting in the way. The first step was to remove those. I cracked open the connections with a 17mm wrench on both ends of the lines and loosened them the rest of the way by hand. The metal tubes easily pulled away. (I put them in gallon plastic zipper bags and labeled them.)

With that, I could get at the electric connections on the glow plugs. Each has a nut that needs a 8mm wrench to remove. By removing the nut, I could then take off one electric wire, a ceramic spacer, and the other electric wire.

Old plug, just removed.

Next, I could remove the glow-plugs themselves. However, I didn’t have the right size wrench. The biggest I had was 19 mm, and the glow plugs seemed to be just a hair larger than that. I used an adjustable wrench to get them started and then used an oversized socket to unthread the glow-plugs the rest of the way.

I had trouble with the plug furthest to the left (closest to the radiator if the engine was still in the car.) Although I completely unthreaded this glow-plug, it still would NOT pull out! I finally figured out that I was spinning only the OUTSIDE portion of the plug, but that the narrow inner part wasn’t spinning at all. It was seized up, stuck in place. I’ve heard of glow-plugs getting gunked-up with carbon, and it looked like this one must have been stuck in it. After breaking the tip off the glow plug with a vise-grips, I started fooling around with several small pry bars. Since the threads were all the way out of the engine block, I figured it was just carbon holding the plug in, and with some prying, I was eventually able to get it out.

Carbon build-up

Looking through the glow-plug holes, I could see that all of them had some carbon build-up, but that last one was the worst. I’ll have to buy or build some sort of a reamer to clear out the holes before installing the new plugs.

Old vs New

Comparing the old glow plugs to the new, one physical difference is pretty obvious. The old plugs have a loop on the tip. This is so that the current can travel through the plug and on to the next one. They are all connected in series. The big downside is that if one glow-plug fails, it breaks the circuit and they ALL stop working.

On the new style plugs, current goes from the power source, through each glow-plug in parallel, and then grounds through the engine block. These make more heat faster, for easier engine starts, and if there is a problem with one glow plug, it does NOT interfere with the operation of the others. I’ll also be interested in finding out how much current these plugs pull, as I will need to know that so I can get a correctly rated relay and fuse for a glow-plug momentary-on button.

For now, the old plugs are out. Next step is to figure out how to ream the carbon out of the holes. After that, I can get the new plugs in, wire them, and test them out.

Progress on the “Super-Truck” project might be slow, but it always feels good when I get at least a little something done on it.

Til next time, stay CHARGED UP!



UPDATE: I just tested one of the new glow-plugs, running it to a 12V battery, and it pulled about 8.5 amps. That’s around 100 watts per plug. Imagine the heat of a 100-watt light bulb, concentrated down to the tip of a pencil. Yowza, that’s hot! Looks like I’ll be needing a 40 amp relay to run the glow-plugs in the finished vehicle.


Dynasty IT Micro-Pickup NEV and Test Drive

by Ben N on July 10, 2014

This past weekend, a friend dropped off a Dynasty IT in my driveway. This IT is an adorable tiny pickup truck that’s in the NEV class. That means that it’s perfectly street-legal, but federal regulations restrict it by law to a 25 mph top speed, and use on streets of 35 mph and less.

My friend had just replaced the batteries in the truck, but when he hooked everything back up, it just plain didn’t work! So, he brought it over to me for a second set of eyes to see if I could figure it out. After checking over all the fuses and other obvious likely problem points, I started working on troubleshooting the motor controller itself, only to finally stumble on the one disconnected wire he missed during the upgrade. Once hooked back up, I took the vehicle out for a spin to see how it performed.

It really is a fun little vehicle. Acceleration is pretty peppy. There’s plenty of head-room and the simple mesh seats are surprisingly comfortable. This particular one was upgraded to an AC motor and matching Curtis 1238 AC controller. AC is lower maintenance, more efficient, and offers regenerative braking.

The back of the vehicle is rather interesting. It’s sort of a deep pickup truck bed, but has more of a hatch-like tailgate. On the other hand, it also has a third door that lets you walk right into the cargo area. Not only that, but the cargo area is rated to carry 1000 pounds of weight! While not designed to tow, this little truck can HAUL!

The overall feel of the vehicle is pretty good. The frame is a hefty aluminum honeycomb and the body is all fiberglass. The front is a nice windshield and the doors have real handles, locks, and manual window cranks. There’s an electric defogger/defroster.

Here’s some of the key features of this particular model.

  • 2007 Dynasty IT utility vehicle
  • All electric drive-train – 72V system – New batteries
  • Front-wheel drive
  • AC Electric Motor (22 HP peak)
  • AC motor controller (Curtis 1238) with regen
  • 1000 watt 120V AC battery charger (Zivan NG1 – charges from regular wall outlet)
  • Aluminum frame/fiberglass body (Nothing to rust)
  • 1000 lb. cargo capacity.
  • Seats 2
  • 30-mile range
  • Third door for easy access to cargo area (great for a dog, large tools, etc.)
  • Electric defog/defrost
  • Less than 1000 original miles on the odometer.

NEVs are interesting vehicles. They aren’t quite a “real car”, but they can be EXTREMELY useful and do it all without using a single drop of gasoline. Maintenance is almost nothing. Plug it in at night and add some windshield washer fluid every once in a while. They work GREAT for a particular niche of people – those who live in town or a neighborhood with 25 mph streets. Frankly, that’s most cities. On the other hand, I live about one mile AWAY from the 25 mph zone. The main road in front of my house is 45 mph, and I can’t get to anywhere without crossing it. For somebody living only a mile south of me, they could get to the library, bank, grocery store, and everything else a person needs to do in a day in this handy little truck.

If you haven’t already, take a peep at the YouTube videos at the top, and you can get a tour of the vehicle and come along on a little test-ride with me.

‘Til next time, stay charged up!



PS: The owner of this vehicle would like to sell it. He’s only asking $3000. If you are interested and would like to see the vehicle or take it for a test ride, please let me know. Vehicle is in south-eastern Wisconsin and a reasonable distance from Madison, WI and Chicago IL.