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1961 Volvo PV 544 to EV 544 - Build Thread

14829 Views 188 Replies 14 Participants Last post by  lordmundi
Hello All!

I pondered what to do to this car for over 1 year since driving it home. Yes, it was the first project car I had not needed a trailer for! I have travelled as far as Southern Cal. to pickup other projects with a trailer in tow. Never one only 15 miles from home! And so cheap ($2500) for a running vintage car!

Because the starting point was so favorable, it was tempting to simply do a stock restoration. But then I started digging and found the engine and tranny were not original, coming from a newer Volvo. I felt like it opened the door for a restomod. I am soon 72 years old and have always enjoyed a challenge. My last build was a traditional hot rod which included at totally fabricated frame and flat head V8. Parts were either already in my shop or sourced from multiple swap meets and online sales The various parts spanned years 1928 to 1962 in vintage. I also upgraded a 1958 MGA Coupe to a 2000 Miata drive train. I have done a 1956 F100 PU with a 90's era drivetrain from a T-bird SuperCoupe. This past May I drove Rte. 66 in it. 6000 miles round trip. So major technology jumps with previous projects has been accomplished. And I drive the things! But ICE to EV??? Before last year I didn't even know what those acronyms stood for!

I reviewed the topics I was to cover with my first post, and I can see the logic to determine where everyone enters this EV game. So I can fabricate, I can visualize, I can drive. But this EV thing was a bit intimidating. Then I took a ride in a modern EV and got sucked in! With your help, I hope to make this car an almost daily driver. I am planning for 80 - 100 mile range. I also want to approach this incrementally, both for affordability, but also because I like to mock up restomods to present a car look like it could have come from the factory that way. I have become adept at doing this, but it has always been by trial and error with lots of cardboard and wood mock-ups. I have fabricated things multiple times to get it looking right (as well as for structural integrity!).

I hope I can present this EV conversion similar to my other less radical projects. I want the motor with controller to take center stage, so no battery box on top of it, even though there is a lot of room under the bulbous hood. Likewise, I doubled the HP and Torque on that MGA mentioned above, and it suddenly became a fun (not to mention dependable) sports car! While I will only have a marginal HP jump in my chosen EV gear, I am pretty sure the torque value and dependability factors will be satisfying enough!

That all said, I have been working with EVWest to gain a system understanding and with a local Electrical shop that has dabbled in EV development for the last 10 years. EVWest had done a Volvo P1800 several years ago and just this past week we were able to confirm a match to my Volvo bellhousing and flywheel. So I have the adapter/coupler on order with them. I also have a Hyper 9 HV motor system with chill plate and front motor mount on order with the local shop. Saved much on freight by finding a local source for that! I have other components pre-selected from both EVW and locally, but again will use these first major pieces to anchor the mock-up stage. So because the adapter is a long lead item, I will probably be doing more restoration type stuff in the interim, so bear with me.

I attach pix of the car, the voluminous engine bay and similar trunk. I do plan to put at least some battery packs in the rear where the gas tank came from. However only 100-120 lbs or so to help keep within original weight trim. Which I think will be okay, with so much room in front. But again, I want to showcase the motor. Not the battery packs.

Looking forward to hearing comments from this valued knowledge base in the months ahead!

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John Larsen
Lynden, WA
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Not 5 minutes after my response, the cat threw up right in front of me on the living room floor. Dang, Mammas gone to bed, so options were: 1) Finish my wine and go to bed, leaving what appears to be a ginger bread man and a EV BMS module outlined on the floor, 2) take a picture and clean it up so at least I get some sort of recognition for valor and 3) Just clean it up and act like nothing happened.

Yep. Real Man here. Option 2 it is, AND text it to her like right now!!

See what you started??
Slowed down by bitter cold weather that included winds with dust bowl features. At one point we could not see the neighbors house 1000 feet away. Could not imagine living through that type weather in 1930 Oklahoma. Even so, I did a few things, not least of which is installation of my hidden "fuel" door. Provides double weather protection to the J1772 receptacle. Also looks better than an exposed port.

Major charging system is on order and after discussion with the supplier, was assured that the Master Control Unit (MCU) is now stable and should require no more patches or work-arounds.

Starting to study wiring diagram and as close as I can figure, my traction battery cables and motor controller should not require larger than 1/0. It seems many people are using 2/0 for smaller systems, but the amp tables say this may be over kill in some applications. On the otherhand, I don't want t degrade performance, but the potential for smaller wire is one reason I went with the Hyper 9 "high volt" (HV) system.

Does anyone have the Hyper 9HV system component diagram with the smaller wire sizes posted? I realize distances would factor in, but the loads of the smaller stuff are relatively low.

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OK dust bowl is an opportunity where you park the car outside and save yourself some labor in body prep. I guess it wasn't cold enough for a CO2 blast?

Your runs are pretty short and you should be fused and current limited to what the manufacturer of the cable recommends for max temp rise of the insulation being used, anyway.

Double weather protection? So two things to get iced closed?
Should have charging stuff by next week, so in the meantime, a little restoration work. Painting the trunk where I will mount the charging equipment. Not sure where to locate the contactor and fuse box. May go closer to the motor up front.

And to ensure this thing is QUIET, I have installed sound dampening mat in the cabin. I ran out of material, but will do the inside of the doors and front fenders inside the kick panels too.

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I just pulled the original Volvo gauge pod, as evidenced by the blood running down my hands - as if this were a critical care operation.

I would like help (I will post this as a new topic in the forum too) to see what people have used out there to try and utilize the original frame as shown. The part that I visualize to be available for EV gauges is the window above the VOLVO insignia. It is 2.25" wide and 12" L at the center of the sloping part.

Second choice would be to use the entire opening, getting rid of the vintage Volvo insignia altogether. .That opening would be 3.5" x 13". Or maybe save the insignia in the center, with two 3.5" x 4" spaces on each side.

Either way, I have a friend who does magic with a small CNC plastic milling machine, so he will be able to create any facia as needed.

It would be cool to use the vintage ribbon style speedo, but I don't even know if it works. And it runs right down the center.

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couldn't resist putting the carpet kit in. It came with the car and I never even looked at it, but it is brand new and even came with a sound pad. More quiet is good!

May leave it there just to flatten out and a good sleeping spot if I get tired.

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Received the charging system on Monday and started mocking up for what I hope is the best location to preserve trunk (boot) space. I installed a vertical bulkhead up where the rear seat mounts that gets everything up and away from the floor.

I haven't decided on the battery placement with two options shown. If I can get a more square shape, I would like it hidden behind the spare tire. The space next to the charger might be a good spot for the contactor/fuse box.

I will officially start wiring tomorrow! I became aware today, that there is not really a good supply house for EV related things in my area. At least for stuff that actually looks like it might belong in car. I guess I will continue with online shopping. Is there one good value, single go-to resource out there?

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It would be cool to use the vintage ribbon style speedo, but I don't even know if it works. And it runs right down the center.

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That speedo is a vintage highlight. Give him a try, please. If you find a mechanism that moves the pointer, it should be easy to power it with a tiny stepper motor and a microcontroller. Currently I'm doing this with my mechanical round instrument. The odometer will be replaced with an OLED display. You get really tiny ones of these that fit as a replacement for the numeric meters.
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That speedo is a vintage highlight. Give him a try, please. If you find a mechanism that moves the pointer, it should be easy to power it with a tiny stepper motor and a microcontroller. Currently I'm doing this with my mechanical round instrument. The odometer will be replaced with an OLED display. You get really tiny ones of these that fit as a replacement for the numeric meters.
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Thanks for the feedback - I will be anxious to hear how your solution works. It will be awhile before I move on the gauge selection, so will continue to study options to make the vintage speedo part of the gage pod.
Did the same on this Volvo speedo.
Since he is keeping the M40 the mechanical side keeps working.
So indeed a nice opportunity to modify the old temp end fuel meter.
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We will be talking Erik!
Following my charging system location game, I really did not like the fit of the stock battery, taking up bulkhead space for a possible contactor box. I dredged through a number of forum posts thinking I should be able to get away with a smaller battery since the starter cranking function is deleted. I discovered that a garden tractor variety has been used with success. I just happened to have my wife's lawnmower battery inside for the winter. (Yes, I said wife's lawnmower! :) ) It is a much better space saver. But if I can find an AGM with enough reserve power, it will get even smaller, possibly hiding the thing behind the spare tire.


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I confirmed my mechanical ribbon speedo works, so the original gauge pod is definitely in play! I tested it with a drill motor (battery operated of course) connected to a piece of cable I found. I discovered why the PO never hooked it up - it was the wrong cable at both ends!

Thanks to Lars who sent me his blog showing the beautiful work he did on his dash. It appears to be a whole lot more to learn! I was jus starting to get a handle on how all the major EV components function, after about the 6th repeat on various videos and diagrams! This dash pod will probably be deferred to the end of the project or winter past time. It's just good to have the end game in mind!

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I have been obtaining both 12V and HV items to start laying out my contactor box(es). I have been following the attached diagram designated for the lower voltage Hyper 9 as there does not seem to be an HV version out there. So I upgrade as required. The 9-HV system is also 500 amp rated, so I am revising that as well.

I am puzzled by the use of a 12V contactor for the DC-DC and the way it is stacked onto the B+ leg of the main contactor. Thunderbolt simply shows an "enable" switch on one leg of the DC-DC converter which this contactor serves.

Could I simply use a second Key Switch HV relay in lieu of the 12V contactor and graft it into the one wire that TBM designates?


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That diagram is worthlessly zoomed in, or do I lose the game of guessing where those contactor connections go?
Oh come on Remy, that thing has been posted so many times on the forum, how can you not know where to find the original?

Here you go...


Many DC-DC are over a kilowatt in size, so you'd need a pretty hefty relay. I think it's called a contactor...

That diagram is unsafe and should be revised, imo - far from a guide on how to do it. It has 150V cables running outside the battery box that cannot be shut off, unless you get electrocuted first and then your charred remains act as a <0.25 ohm resistor to pop the fuse 💀

Someone clearly assumed they could extend two battery boxes as one by joining via conduit (yet do not spec that the shutoff switch must be mounted on a battery box), but a first responder's chop saw would beg to differ. DON'T USE THIS DIAGRAM. You can't have more than 60V outside the box(es). Unless those are <60V boxes...

I'm guessing this started out as a singular battery box and got modified by an indifferent person who only cared about connectivity. Epic fail.

These guys are teaching a course, if that diagram really is theirs and the boxes are >60V 🤦‍♂️
Well, I picked it off their website...

My body has way more than .25 ohm resistance. Just ask my wife.

Can you refer me to a more secure example? This thing is floating out there, and many forum members seem to be referring to it!

At least in my naiveté, I smelled a rat!
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