EZGO TXT DC to AC conversion

[Jinman08]

I came across a guy giving away 3 carts on facebook marketplace. Based on my conversation with him I'm pretty confident they are left over donor carts from a large lot. They dont have batteries, motors or controllers. I have an AC motor from the RXV that I rebuilt last winter thanks to the help of this forum!

Is it possible and if so what all would need to be changed to put the Iskra AMT7109 AC motor I already have into the TXT cart? At a quick glance the axle housing looks like the bolt patterns are the same, I'll test fit it tomorrow. I'm not after more power or for the cart to be fast, I'm planning on building it for my kids to drive. I figured since I have to buy a controller no matter what I do I might be able to save some money by using the motor I currently have and as I understand it the AC motor is more efficient/less taxing on the batteries.

Any help or guidance is greatly appreciated. I tried searching and found people talking about DC to AC conversions being done but not how it was done and I've found complete kits from Navitas but I would like to use the motor I already have and while I'm sure I can get the parts individually without the motor I dont know if it'll work with the AMT7109 motor.

[Imapled]

Originally Posted by Jinman08

Is it possible and if so what all would need to be changed to put the Iskra AMT7109 AC motor I already have into the TXT cart? At a quick glance the axle housing looks like the bolt patterns are the same, I'll test fit it tomorrow.

I have test fit one on a TXT axle and have plans to get it running but, it is not a simple project nor would I recommend it generally. It takes a lot of specialized knowledge and custom programming of an AC controller.

Originally Posted by Jinman08

I figured since I have to buy a controller no matter what I do I might be able to save some money by using the motor I currently have and as I understand it the AC motor is more efficient/less taxing on the batteries.

You won't really save on reusing the motor. There are only a few options for AC controllers that I am aware of (there may be more) for a TXT. One is the Navitas TAC2.0 TXT48 controller and Curtis makes AC controllers that may work as well. I am only familiar with the Navitas TAC2.0 TXT48 setup. Bob Boyce may have a different opinion on how a Curtis controller could be used.

Here is my input on the TAC2.0 from Navitas w/ a TXT48 harness.

1. You will need either a PDS or TXT48 wire harness right off the bat. Navitas makes a PDS -> TXT48 harness adapter that you can use if the carts have PDS harnesses. If the cart is series or DCS you will need to replace the harness. If this is the case put a TXT48 harness in.

2. You will have to rewire a bunch of ends to adapt to the motor and another part from Navitas from their DC to AC conversion. If you look at the documentation for the TXT48 TAC2.0 you will see which plugs will need to be clipped and either new plugs put on or direct-wired.

3. You will need to custom program the TAC 2.0 controller. For that you will need the OEM or Developer level software from Navitas. Its not commonly given out. If you can manage to get it you will have a lot of custom programming to do. Not for the faint of heart and if you fail to figure it out you will be stuck with a controller, motor and a cart that isn't working. You have to figure out what to do with the brake... Disable it? Program it in? Use it as an anti-roll away? You will be basically on your own to figure it all out. It is not a supported motor profile in the TAC2.0.

I really caution you against doing this unless you are a motor expert and are comfortable with programming. It's not an easy project to do. It isn't going to save you any money really. You might be better off selling the RXV motor you have and using the cash to purchase another used DC motor and controller that will work with whatever wire harness is already in the cart.

Cheers,
Imapled

[Jinman08]

Originally Posted by Imapled

I have test fit one on a TXT axle and have plans to get it running but, it is not a simple project nor would I recommend it generally. It takes a lot of specialized knowledge and custom programming of an AC controller.



You won't really save on reusing the motor. There are only a few options for AC controllers that I am aware of (there may be more) for a TXT. One is the Navitas TAC2.0 TXT48 controller and Curtis makes AC controllers that may work as well. I am only familiar with the Navitas TAC2.0 TXT48 setup. Bob Boyce may have a different opinion on how a Curtis controller could be used.

Here is my input on the TAC2.0 from Navitas w/ a TXT48 harness.

1. You will need either a PDS or TXT48 wire harness right off the bat. Navitas makes a PDS -> TXT48 harness adapter that you can use if the carts have PDS harnesses. If the cart is series or DCS you will need to replace the harness. If this is the case put a TXT48 harness in.

2. You will have to rewire a bunch of ends to adapt to the motor and another part from Navitas from their DC to AC conversion. If you look at the documentation for the TXT48 TAC2.0 you will see which plugs will need to be clipped and either new plugs put on or direct-wired.

3. You will need to custom program the TAC 2.0 controller. For that you will need the OEM or Developer level software from Navitas. Its not commonly given out. If you can manage to get it you will have a lot of custom programming to do. Not for the faint of heart and if you fail to figure it out you will be stuck with a controller, motor and a cart that isn't working. You have to figure out what to do with the brake... Disable it? Program it in? Use it as an anti-roll away? You will be basically on your own to figure it all out. It is not a supported motor profile in the TAC2.0.

I really caution you against doing this unless you are a motor expert and are comfortable with programming. It's not an easy project to do. It isn't going to save you any money really. You might be better off selling the RXV motor you have and using the cash to purchase another used DC motor and controller that will work with whatever wire harness is already in the cart.

Cheers,
Imapled

Thanks for the reply and the info!

The cart is a PDS and I already have a TXT48V harness as well (I bought it when I got my RXV. There was a large learning curve. Lol)

With directions and by that I mostly mean pictures I can figure out just about anything related to wiring or fabrication. But I am not an expert at anything, least of all programming.

As for the brakes I believe the cart has a physical brake which is good enough for me but it would be awesome if it were possible to get the regen braking functioning.

All in all if this is something that's highly technical and requires expert level knowledge to do I will just go with a 48v DC motor. Since I already had the motor I just want to see if this is something I'm capable of doing.

[agpfl]

I was planning a similar project with a PDS. Wanted a TXT running an AC motor. I purchased a donor RXV for the project. The plan was to use the AC motor with a curtis controller. Between the throttle type, brakes, and low voltage items that need to be accounted for it did not make sense. I then was just going to use the motor as you are suggesting with a Navitas controller. This would work, but you need to either remove the motor brake completely or just remove the disk from inside of it. I ended up just fixing up the donor cart and selling it. I purchased the complete DC to AC kit. Since I had a PDS wire harness, I attempted to repin the molex connector to the TXT48 pinout. Turns out that the logic power is spliced from 5 connections into 1 pin on the molex connector, whereas the PDS home runs each one. I ended up getting a TXT48 wire harness and extending the 3 wires for the FnR switch (TXT48 between legs vs. PDS on dash)

[Jinman08]

Originally Posted by agpfl

I was planning a similar project with a PDS. Wanted a TXT running an AC motor. I purchased a donor RXV for the project. The plan was to use the AC motor with a curtis controller. Between the throttle type, brakes, and low voltage items that need to be accounted for it did not make sense. I then was just going to use the motor as you are suggesting with a Navitas controller. This would work, but you need to either remove the motor brake completely or just remove the disk from inside of it. I ended up just fixing up the donor cart and selling it. I purchased the complete DC to AC kit. Since I had a PDS wire harness, I attempted to repin the molex connector to the TXT48 pinout. Turns out that the logic power is spliced from 5 connections into 1 pin on the molex connector, whereas the PDS home runs each one. I ended up getting a TXT48 wire harness and extending the 3 wires for the FnR switch (TXT48 between legs vs. PDS on dash)

Running the motor without the motor brake wouldnt be a problem at all. When I tore it apart I found that the motor brake had been reclocked 3 times and the bolts had broken off all three times. So I had to drill the bolts out and then took it to a welding shop to have the holes filled. I still need to tap the three bolt holes if I were to put the brake back on.

So you're saying it was not necessarily impossible to use an RXV motor but it was considerably more complicated than what sounds like an already fairly complex project using the Navitas DC to AC kit?

I didn't completely understand why you opted to use the TXT48 harness instead of the PDS harness? Did that make it more straight forward/fewer harness modifications?

The cart is a PDS and I have an extra TXT48 harness but yalls responses are making me think this might be I'm too far outside of my experience. But I'm all for one of yall convincing me I should do it. Lol

[Imapled]

Originally Posted by agpfl

I ended up getting a TXT48 wire harness and extending the 3 wires for the FnR switch (TXT48 between legs vs. PDS on dash)

Navitas sells a PDS -> TXT48 harness adapter now.

Part #: 40-000653

Makes using the PDS harness really easy. I used it on my TXT install. But, installing a TXT48 harness, in the long run, is a better option.

[Imapled]

Originally Posted by Jinman08

So you're saying it was not necessarily impossible to use an RXV motor but it was considerably more complicated than what sounds like an already fairly complex project using the Navitas DC to AC kit?

It can be done but, you have to custom program a motor profile. Which means you need to reach out to Navitas to see if you can get the OEM programming software so you can setup the motor profile correctly. They don't have a motor profile in the general settings for a TXT48 setup. You technically can do it but, you have to custom program it.

Originally Posted by Jinman08

I didn't completely understand why you opted to use the TXT48 harness instead of the PDS harness? Did that make it more straight forward/fewer harness modifications?

Probably at the time the part that I listed above wasn't available. It is now and you can use it for a PDS harness. (I have used it on my personal cart.)

Originally Posted by Jinman08

The cart is a PDS and I have an extra TXT48 harness but yalls responses are making me think this might be I'm too far outside of my experience. But I'm all for one of yall convincing me I should do it. Lol

It is not easy to do. I don't recommend it unless you really understand how AC motors work and how to program them properly.

[cgtech]

Considering what must be done to correctly "characterize" the motor to the controller, you are probably better off selling the motor to someone whose rxv motor has a failed temp sensor (rxv temp sensor is not replaceable & requires a new motor). I'm interested in hearing how you "rebuilt" a rxv motor, since it has no brushes & comm to "wear out". It has a "encoder" (replaceable), bearing (replaceable), bearing & encoder are all-one-part on many of those, and a temp sensor (not replaceable). The rest of the parts are good for the life of the motor. I have seen only 1 bearing failure (even with lots of 9,000 rpm use). What did you rebuild? Temp sensor failure is the only thing I have ever seen that has required a full motor replacement on a rxv. Wait, I take that back, I did see an rxv that had acid corrosion inside the motor, that killed it.

Get a HPEVS ac system, more powerful than stock rxv motor anyway. Or Navitas if you prefer. I like the HPEVS because it uses a curtis controller, which I can do anything I want with. Not so with navitas.

I did a "major conversion job" to put that HPEVS setup in a rxv once, trust me, it's a job to do in a rxv (but cake in a txt). And it was a beast (it's the owners hotrod).

[Jinman08]

Originally Posted by cgtech

Considering what must be done to correctly "characterize" the motor to the controller, you are probably better off selling the motor to someone whose rxv motor has a failed temp sensor (rxv temp sensor is not replaceable & requires a new motor). I'm interested in hearing how you "rebuilt" a rxv motor, since it has no brushes & comm to "wear out". It has a "encoder" (replaceable), bearing (replaceable), bearing & encoder are all-one-part on many of those, and a temp sensor (not replaceable). The rest of the parts are good for the life of the motor. I have seen only 1 bearing failure (even with lots of 9,000 rpm use). What did you rebuild? Temp sensor failure is the only thing I have ever seen that has required a full motor replacement on a rxv. Wait, I take that back, I did see an rxv that had acid corrosion inside the motor, that killed it.

Get a HPEVS ac system, more powerful than stock rxv motor anyway. Or Navitas if you prefer. I like the HPEVS because it uses a curtis controller, which I can do anything I want with. Not so with navitas.

I did a "major conversion job" to put that HPEVS setup in a rxv once, trust me, it's a job to do in a rxv (but cake in a txt). And it was a beast (it's the owners hotrod).

Rebuilt may not have been the best characterization. The encoder bearing was rusted and while it wasnt seized it definitely was spinning smoothly so I replaced that. The rotor and stater had a fair amount of rust and the windings were heavily corroded so I cleaned them as per BobBoyces instructions. Then the motor brake had been reclocked 3 times with the bolts having been broken off in the motor end plate each time so I drilled out all the bolt remnants and took the end plate to a local machine shop and had them fill the holes so I could reinstall the motor brake back with the bolts in the thicker pads the bolts were originally screwed into.

[Jinman08]

Its sounding like to use the RXV motor I have is more than a little beyond my skill set so I think I'm just gonna see if I the harness and maybe the controller are salvageable and hopefully get away with just buying a new or refurbished DC motor.