2004 EZGO TX PDS 36v Motor Smoking

[yurtle]

Originally Posted by JohnnieB

1. What was voltage on controller side at this point in time?
2. Normal
3. You're, probably reading the charge on the dozen or so filter capacitors connected between B+ and B- inside the controller. It take several minutes for them to discharge.
4. Welded solenoid contacts won't stop cart from running. It will run slowly (reduced performance mode) and you should get a 3-2 error code in diagnostic mode, if the beeper worked.

A smoking motor is a very bad sign, and if the motor had a catastrophic failure, the controller may be gone also.

I'd start by checking the motor. As mentioned, it is 15 years old, so it could use a new set of brushes and a new bearing, as well as a good cleaning.

Remove the four cables. Leave speed sensor in place for now. Be sure to use two wrenches when loosening the nuts holding cables on studs. Place one wrench of bottom-most nut to keep stud from spinning and doing bad things inside motor.

With cables off, measure the armature and field resistances with an Ohmmeter.

A1->A2 should be between 0.3Ω and 1.0Ω
F1->F2 should be between 1.0Ω and 2.0Ω
A1->F1 should measure OPEN
F1->Motor Case should measure >5MΩ

If it passes those tests, it's probably okay, but most like need to be serviced due to age.

As I mentioned earlier, the Service Manual has good instructions, even if you can't find an exact match as far as year. Just make sure it's a PDS manual. My '89 series motor brushes were fine, according to the manual, but I did replace my bearing and clean up the commutator with a ScotchBrite pad. I like those better than emory cloth or worse, steel wool. Don't want abrasives or conductors inside a piece of rotating equipment.

[snuckols64]

Being the impatient person that I am, I had gone through the repair manual trouble shooting and all tests pointed to motor failure. So I had pulled the motor prior to reading this. That said, I ran the OHM tests with the following results in order:
.023
.000
.043
.005

Is ok that I tested with the motor being out of the machine? Do you think the motor is dead?

[JohnnieB]

Originally Posted by snuckols64

Being the impatient person that I am, I had gone through the repair manual trouble shooting and all tests pointed to motor failure. So I had pulled the motor prior to reading this. That said, I ran the OHM tests with the following results in order:
.023
.000
.043
.005

Is ok that I tested with the motor being out of the machine? Do you think the motor is dead?

Okay to do electrical tests on a motor out of the cart, but don't try to run it. Bearings only on one end of armature shaft, so armature lodges against field shoe when voltage is applied and won't turn.

The first two are mighty low, but not many Ohmmeters are very accurate below 10Ω or so, however the last two indicate shorts between the Armature and Field windings and between the field windings and the case, so the motor is very likely history. Unfortunately, a short between the Armature and Field windings shorts the controller's Armature and Field outputs, so chances are the controller is history also.

The only practical test I know of for a SepEx controller without a SepEx motor to connect it to is the diode test attached below. Different brand controller, but the all work the same. Note: The M- terminal is labeled A! on the stock PDS controller.

If controller is bad, replace it with an Alltrax XCT48400-PDS (or larger) controller. Replace the stock solenoid, which is only 85A and marginal even with a stock (300A) controller. If there is the slightest possibility of upgrading to 42V or 48V battery pack in future, go with the MZJ400-48V, it's coil works at 36V, 42V and 48V.

For motors, you have a wide choice. Depends on what the cart is to be used for.

This is where I get most of my parts: http://www.cartsunlimited.net/

[snuckols64]

Any idea what would have caused motor failure? Just old?

[JohnnieB]

Other than mechanical failures, heat is what kills motors.
Running a PDS cart slow speeds (walking speed or less) or a top speed, runs the motor in less efficient RPM ranges and they run hotter. Pulling heavy loads and climbing steep hills also cause motor heat.

What fails is the insulation on the wires used in the armature and field windings and the hotter the motor runs, the shorter its lifespan. Stalling a motor can take it out within a few moments. Taller than stock tires means the motor turns slower for any given speed, which in turn increases motor heat.

A stock PDS motor is one of the least tolerant of heat, but it does okay with stock controllers or aftermarket ones with 400A or less throughput, or turned down to 400A or less.

[snuckols64]

My wife uses the cart for just running around the neighborhood. There is one long steep hill that she climbs daily during the school year when she picks up the girls from school. It's lifted and has 23" tires.

Thinking about purchase this kit to get back up and running. Thoughts?

[snuckols64]

Originally Posted by JohnnieB

Okay to do electrical tests on a motor out of the cart, but don't try to run it. Bearings only on one end of armature shaft, so armature lodges against field shoe when voltage is applied and won't turn.

The first two are mighty low, but not many Ohmmeters are very accurate below 10Ω or so, however the last two indicate shorts between the Armature and Field windings and between the field windings and the case, so the motor is very likely history. Unfortunately, a short between the Armature and Field windings shorts the controller's Armature and Field outputs, so chances are the controller is history also.

The only practical test I know of for a SepEx controller without a SepEx motor to connect it to is the diode test attached below. Different brand controller, but the all work the same. Note: The M- terminal is labeled A! on the stock PDS controller.

If controller is bad, replace it with an Alltrax XCT48400-PDS (or larger) controller. Replace the stock solenoid, which is only 85A and marginal even with a stock (300A) controller. If there is the slightest possibility of upgrading to 42V or 48V battery pack in future, go with the MZJ400-48V, it's coil works at 36V, 42V and 48V.

For motors, you have a wide choice. Depends on what the cart is to be used for.

This is where I get most of my parts: http://www.cartsunlimited.net/

I really appreciate all of your help and apologize for the 1000 questions. Tested the controller this morning and got the following readings in order:
.596
.319
.626
.629

They were a little outside the normal range but close. Should I replace it?

[JohnnieB]

Originally Posted by snuckols64

My wife uses the cart for just running around the neighborhood. There is one long steep hill that she climbs daily during the school year when she picks up the girls from school. It's lifted and has 23" tires.

Thinking about purchase this kit to get back up and running. Thoughts?

The red highlighted statements answer the what caused the motor failure question.

You've got the right idea in general, but the wrong controller, cables and vendor, and there are better motor choices. Buggies Unlimited doesn't have a stellar reputation to say the least.

If you appreciate the help received on this forum, it would be appropriate to purchase the parts from one of the forum sponsors: http://www.buggiesgonewild.com/site-sponsors.php

The Curtis controller might be programmable for performance characteristics, but requires a Curtis programming tool that is sold separately, or you have to find a dealer or technician that has one and pay them to program your controller. Also an adapter cable is needed to connect the four plugs of your cart's wiring harness to it.

On the other hand, an Alltrax XCT48500-PDS controller is user programmable via USB cable and free software. Also has four jacks matching the four plugs on a 36V PDS wiring harness. In addition, the XCT has multiple user profiles that can be customized for different drivers, or different terrain and users can be changed via a switch on the dash or somewhere convenient.

With the 23" tall tires, you'll need 2Ga cables rather than 4Ga. The tire height costs you about 22% of the torque available where rubber meets road and the motor will be turning 28% slower, so the motor (any motor installed) will be drawing a lot of amps accelerating from a standstill and going up hills.

The motor looks to be the high torque version of the stock motor that was burnt out by the tall tires and steep hill. A better choice would be a motor in a longer case, which gives it more torque and more heat dissipation. The one I have has 30% more torque than stock and stock max RPM for applied voltage. With the 23" tires and daily hill climbs I'd go with 40% more than stock torque or greater.

E-mail Scotty at Carts Unlimited scottyb@cartsunlimited.net, tell him what you've got and what you want to use cart for and he'll set you up with what you need.

FWIW: Other than being a satisfied customer, I have no vested interest in any of the site sponsors.

[JohnnieB]

Originally Posted by snuckols64

I really appreciate all of your help and apologize for the 1000 questions. Tested the controller this morning and got the following readings in order:
.596
.319
.626
.629

They were a little outside the normal range but close. Should I replace it?

Each diode show on drawing has to be measured in both directions to determine if they are good or bad.

With the 23" tires and a steep hill climbed daily, I'm surprised it didn't fail long before the motor smoked.

This has been mentioned yet, but your cart needs to be upgraded to 42V or 48V to cope with the tall tires and daily hill climb.

I'm at 42V and I'll most likely go to 48V when I have to replace my current set of batteries. I've got steep hills I climb every time I take my cart out, but I have tiny tires, so they give me a slight torque gain rather than a torque loss. Even with 42V, I can spin my motor faster than the manufacturer's max recommended RPM on level pavement, but going to 48V will reduce the amount the cart slow going uphill and with the XCT controller, I can limit the motor's max RPM to max recommended RPM, or slower.

[snuckols64]

Originally Posted by JohnnieB

Each diode show on drawing has to be measured in both directions to determine if they are good or bad.

With the 23" tires and a steep hill climbed daily, I'm surprised it didn't fail long before the motor smoked.

This has been mentioned yet, but your cart needs to be upgraded to 42V or 48V to cope with the tall tires and daily hill climb.

I'm at 42V and I'll most likely go to 48V when I have to replace my current set of batteries. I've got steep hills I climb every time I take my cart out, but I have tiny tires, so they give me a slight torque gain rather than a torque loss. Even with 42V, I can spin my motor faster than the manufacturer's max recommended RPM on level pavement, but going to 48V will reduce the amount the cart slow going uphill and with the XCT controller, I can limit the motor's max RPM to max recommended RPM, or slower.

Would it be possible to purchase a kit that could be upgraded to 42v and/or 48v a little ways down the road? Just don’t have a ton of cash the throw at it right now.