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1986 CRX EV conversion (Nissan Leaf Donor) - Now Running and Misc upgrades

75108 Views 691 Replies 24 Participants Last post by  windraver
I'm new and am planning to convert my 1986 Honda CRX into an EV. I have a 2015 Fiat 500e for parts but from what I know so far, the Fiat is sensitive and difficult to use for parts. I believe it uses the Bosch 180/120 based on my Google fu. I've sourced the wiring diagram for the vehicle and confirmed it is indeed a 3 phase AC motor, one for each phase, 2 wires to sense temperature, and another 6 for the resolve (excitor, sin, cos). The biggest challenge is that Fiat uses canbus and the controller, inverter, battery, and more likely will not operate without all the parts. The car almost disabled itself when I changed the radio to android auto makes a good example. I am studying how canbus works in order to see if I can either ignore errors or maybe even hack the system to work.

As back up if I have to build from scratch, I have a separate thread pending approval where I'm asking about the compatibility of the Bosch SMG 180/120 with the Scott drive 250 AC controller.

Also I'm reading I might need an inverter? And what else? I'm still digging through the site trying to figure out what are all the parts needed to run an EV with an AC motor, which seems to be more complex and less popular than running DC. So guides or hints are welcome as I learn the anatomy of an EV.
Edit (2021-12-06):
Current project is now to convert the 1986 Honda CRX using a 2013 Nissan Leaf as a donor car in combination with the Resolve-EV Controller.
Edit (2021-12-23):
Project has begun; Battery Dropped; still need a machine shop to make parts.
Edit (2022-07-14):
Car has been running since June 2022. Car has been inspected by the California Referee Station and certified as an EV. DMV has issued registration though they're still trying to figure out internally how to actually label my car as an EV.

My latest work on this build has been to upgrade the battery from 24kwh to 40kwh. Batteries are installed but I still am working out the BMS issues as a bruteforce upgrade doesn't accurately recognize the battery capacity differences.

The to-do list is on-going and always evolving so although the car is running, I'm likely to be doing some new upgrade or change all the time.
Edit (2022-10-23):
Started building a battery box which is the "final battery" box. Still in the planning state but measure many times and cut once.
Edit (2022-12-27):
Battery Box is built and now revising the bus bars and BMS connections to the latest design.
Edit 2023-01-10
Got it running on 2022-12-30. And got it back on the ground and took it on a road test 2022-12-31

Been cleaning up and doing misc upgrades since.
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Another idea: Put the piece in an oven at 450-500 F to heat it up, then transfer it out to the garage, put it on the big socket and try the sledgie.

Is there something in the manual that says it can't be removed? i guess it may have been designed that way; if so then it would require machine shop tools to get it apart.
In this manual, theres details on how to assemble only the inboard joint, nothing on outboard joint.

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And some googling had some people saying its not possible... (even though I removed 1 joint)

and well.. we can't just go trusting the internet so I went and grabbed the manual I have and hilariously, it says "Do not try to remove or disassemble the outboard CV-joint."

Took a picture:
Gesture Font Parallel Paper Paper product

But yea, not giving up yet....

My list of things to try:
1. Maybe hammer more? Bigger hammer?
2. Hydraulic Press
3. Drill out the shaft near the snap ring until maybe its so weak I can get the snap ring or shaft out...
4. Wait until those ebay outer shafts come in and see if they fit or work.
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i guess they wanted to make damn-sure that no accidental separation of an outer CV ever occurred--it's not a C-clip, but a Stopper Ring.

i have a friend had a CV come out while driving in a tesla S; took it to the T repair center and they "fixed" it, but it came out again within 10 miles on the drive home; they repaired it again and it seems to be holding okay.
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The ebay joints came in.

Wood Packing materials Packaging and labeling Shipping box Carton

They come with the rings, cage, race, grease, all packed and ready to go.
Automotive tire Automotive wheel system Gas Auto part Wood

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But my luck with this CV outer joint half shaft is terrible. The splines from joint to the wheel hub matches, but the splines from race to shaft do not match. 😢

I would need a smaller shaft in order to fit these CV outer joints. Given also this is an EV conversion, a smaller shaft is also less favorable given the torque and power differences.

So my options now are:
1. Hydraulic press out the shaft from the race (which Honda designed to not be removable)
2. Drill out the shaft and get it out of the race
3. Get a smaller shaft that matches the new outer joints and redo the shafts, or provide the specs for a machine shop to make the shafts per the new joints instead of my prototypes (depends on the shop who will take up this work...)
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Tried a 15T hydraulic puller... Didn't come out.

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Trying to press it out but no luck here.
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I guess if I take it to a shop it has to be more than 15T of force.
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No doubt one of our ME's could calculate the punch force needed, assuming spring steel, if they knew the thickness and circumference of the ring where it's going to shear out.

I would have thought 30,000lb would have done it. Yeesh.
That is UFB, they sure didn't want any outer CVs to fail on the road.

If there is enough meat on the stub side to chuck it in a lathe, then carbide tool bits on a boring bar, carbide drill, etc will get it out.
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Tried a slide hammer like @dddrewski suggested but I don't think it did anything lol

So I went for the drill and grinder.

Motor vehicle Safety glove Workwear Engineering Personal protective equipment

I've drilled a lot of metal over the course of this project and most of my drill bits don't last or handle metal as well as I'd like (even with cutting oil)

but these drill bits I used were amazing. I took the drilling quite slowly with cutting oil and it just worked.

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Drills like butter (slowly)
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A nicely drilled hole

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Next I used a die grinder to grind the hole larger
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Grinded until I could see the space where the snap ring would go.

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A light tap with a hammer/punch and the shaft came out. Flipped it over and hammered out the other side as well. Snap ring was still stuck since it was well lodged/expanded into the race. I had to find some sharp picks in order to finally pry it out. It definitely wasn't going to come out easily...

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With all that, I now have a race/cage/bearing/joint set for the outer hub and I need to next reach out to a shop to get these shafts fabricated.

Motor vehicle Differential Gas Tool Metalworking hand tool

A few things worth noting. The shorter shaft (top with yellow X) doesn't seem to fit either race. It might be slightly damaged from hammering or something.

Both outer races instead fit the longer shaft's (bottom shaft with yellow circle). It also looks like the Leaf side is potentially different as well. I'm going to need to check if the shop can work with these or if I need to make another prototype.

Not pictured, I have two Leaf axles for both left/right. Whats interesting to note here is the Leaf axle has a larger diameter and length. So I could have a shop cut to length, diameter, and splines the Leaf shafts to allow the CRX race to be applied on the outer. This in short means I don't need a shop to fabricate the entire shaft and instead just cut one side to size. A shop with a lathe and a milling machine setup for splines should be able to do the job. I found 1 local shop that might be able to do this.

Alternative, is another company out of state which specializes in custom axles. I believe they're capable at the least of making a custom shaft so I'll need to reach out and work with them on what they need sent over and how their pricing.

One option means I can possibly order "back up" shafts but is likely going to be quite expensive while the other might be cheaper but I probably won't get back-ups.
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Where there is a will, there is a way!
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I can't understand the 0.5mm steps in sizing the drills.

You'd think the intermediate drill size would be a tap drill size...

Do they make those 3-step 8% Co bits only in metric?
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I can't understand the 0.5mm steps in sizing the drills.

You'd think the intermediate drill size would be a tap drill size...

Do they make those 3-step 8% Co bits only in metric?
It seems so
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I can't understand the 0.5mm steps in sizing the drills.

You'd think the intermediate drill size would be a tap drill size...

Do they make those 3-step 8% Co bits only in metric?
I have thought about that a lot myself. 8.8, 10.2 and 10.8 are the most important ones missing for metric tap drill sizes. The .5 drills are actually the most used, as you usually don't want a hammer fit on a bolt with threads.

I guess the assumption is that anyone who cares enough to want the right sizes wouldn't buy a set anyway. I have the DeWALT DT7926, which comes with at least 3.2, 3.3, 4.2 and 4.8, but is missing 8.8, 10.2 and 10.8. It is a VERY good set apart from that detail. Even worse, it doesn't seem like DeWALT even make larger the tap drill sizes, so I can't even supplement the kit. Unless I get 11/32, 13/32 and 27/64, which are close enough for all indented porpoises. But those aren't sold in Europe. What in tarnation?
Is a 6mm the redhaired stepchild of metric bolts?
Looks like it's my turn. Car isnt charging and I have no idea why.

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Charger should be fine. I should have enough range to take the car home and figure it out on the weekend.

BMS doesn't have any weird low cells (whew). I wonder if it's a PDM issue but I don't have a way to read the PDM currently. Hoping I don't have to replace the whole PDM like @Electric Land Cruiser
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Misc tests and observations.

Tried the 120v Nissan Leaf charger, 2 different power flex chargers, and none of them worked.

Drove home because I had enough range and didn't want to risk something dumb happening again. Enabled Regen braking. Observed that I was able to charge with Regen.

Got home. Plugged in via a Tesla Wall Connector with J1772 adapter. It started charging!

Unplugged, plugged in 120v Leaf charger. Didn't charge. Tried Tesla charger again, no charge :cry:

So it's "intermittent"? Maybe. Going to see if I can do the resistor issue test. Common issue for Leafs.
The next time if you get the tesla unit working, let it run until you have about 80% charge before fiddling around with all the swapping out EVSE. The OBC is looking at the pack voltage to see what it needs to control the H-bridge to meet, and it will fault if the pack voltage is out of expected range.

Also there should be some DTCs thrown by the OBC if it cancels charging, maybe laefspy can show them to you?
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The next time if you get the tesla unit working, let it run until you have about 80% charge before fiddling around with all the swapping out EVSE. The OBC is looking at the pack voltage to see what it needs to control the H-bridge to meet, and it will fault if the pack voltage is out of expected range.

Also there should be some DTCs thrown by the OBC if it cancels charging, maybe laefspy can show them to you?
Currently not getting any DTCs at all. I haven't been able to get it to charge since so I might have just gotten "lucky". Even tried driving it and doing some brake regen to see if there was a correlation.

Current Options/Plan is as follows:
  1. Dumb continuity check between J1772 port and PDM. Verify that connections are good.
  2. Research and learn more about how to measure J1772. Example the ground pin and proxmimity detection pin which is ~4.35v.
  3. Try to read the CANBridge output for PDM when trying to charge
  4. ... try other things?
  5. Upgrade the PDM to 2018+, get faster charging, and chademo 😅 (and hope it works)
Noting that car drives. BMS shows proper battery cell voltages. Mtr/inv are not involved and don't have any issues/DTCs.

Only thing I'm also "fixing" separately is low 12v battery voltage. Its been a bit low so I'm charging that up to ensure its not "causing issues".
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Well, that SUCKS :(

If everything worked (charging included) for a while
...& then, suddenly it wouldn't charge
...& also, there is coincidentally a 12V (low voltage) situation going on?

I'd concentrate your efforts there ;)

I've read about a few different EV's having charging issues with a questionable 12V battery
...& others that needed to connect a 12V battery (to "power" the BMS) for bench testing
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An old, weak or worn out starter battery will cause a multitude of faults in an EV; the 12V system is a critical function in an EV.
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12v Battery definitely needs a replacement. It's an AGM that I've been using since 2016 which meets the 7 year average lifetime.

Currently eyeing the Ohmmu LFP 12v battery as its higher capacity but is 42% of the weight (11lbs LFP vs my current 26lb AGM)

There really isn't any "cranking" of a starter on EVs so it actually doesn't require much power to "start" and EV. Really the most critical part is ensure there is enough power to engage the relays and at that point the HV battery begins charging the 12v

Same when charging, the relays will engage and the PDM begins charging the 12v battery which is being used to power the waterpump and various electronics.

I checked and the relays are definitely engaging when the charger is connected. So the car knows I've connected the charger. But the charger doesn't provide power and I'm guessing thats related to either the proximity pilot or control pilot
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Based on the wiki for J1772, I probably need to check why the CP, control pilot is not communicating back to the charger? It seems proximity pilot is working because the car definitely knows the charger is connected. I basically don't hear the charger (wall charger) relay activate and begin providing power.

So either CP wire has issues, or the Leaf PDM has some issue and isn't signaling? More research required.

Reading further, this wiki is really good!

The signaling protocol has been designed for the following charging sequence.[25]

  • supply equipment signals presence of AC input power
  • vehicle detects plug via proximity circuit (thus the vehicle can prevent driving away while connected) and can detect when latch is pressed in preparation for plug removal.
  • Control Pilot (CP) functions begin
    • supply equipment detects plug-in electric vehicle (PEV)
    • supply equipment indicates to PEV readiness to supply current
    • PEV ventilation requirements are determined
    • supply equipment current capacity provided to PEV
  • PEV commands energy flow
  • PEV and supply equipment continuously monitor continuity of safety ground
  • charge continues as determined by PEV
  • charge may be interrupted by disconnecting the plug from the vehicle
The technical specification was described first in the 2001 version of SAE J1772 and subsequently the IEC 61851-1 and IEC TS 62763:2013. The charging station puts 12 V on the Control Pilot (CP) and the Proximity Pilot (AKA Plug Present: PP) measuring the voltage differences. This protocol does not require integrated circuits, which would be required for other charging protocols, making the SAE J1772 robust and operable through a temperature range of −40 °C to +85 °C.
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Ok, going to open the PDM and test the Control pilot.

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