2004 EZGO TX PDS 36v Motor Smoking

snuckols64

Newbie here... I have a stock 36v PDS that stopped moving at all. I have tested batteries and connections, which are all good. When messing around the other day with the wheels off the ground, I noticed that when I held the throttle down I could see smoke coming from the bottom side of the motor. Is this simply mean the motor has gone bad? Could something else be contributing to the smoke or causing the motor to die?

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

Brob1969

Definitely shouldn't see smoke. I would pull the motor and check the bearings and brushes. While it's out, blow out all the dust and debris.

yurtle

And replace the single bearing, which is 15 years old.

The manual in the stickies tells how to check and change brushes.

snuckols64

Went back to try it again today, and for some reason I have no backup alarm. Good battery power, solenoid clicks when throttle is pressed, but no movement and no alarm. Also no smoke. Any ideas?

orangeman6

If you’ve got the solenoid clicking the activation circuit is working, so the low amperage wires/switches are not the problem. You probably need to test that the solenoid is actually engaging and passing current, but one of the gurus will chime in with the exact procedure. I just wanted to suggest that you be careful with how hard you push the cart with the wheels off the ground. You said in the OP “ I held the throttle down”. You didn’t say for how long, but I’ve always read to only do that very briefly, as it is hard on the motor to do it for any extended period.

Brob1969

Sounds like a thorough inspection of the FNR switch is in order. In addition to the motor switching, the FNR has two microswitches, and also is where the reverse indicator is mounted.

The voltage lugs get hot and melt the backer material and eventually the lug pulls away from the contactor. This causes a no movement issue, and could also be the cause of some motor issues if it's not been making good connection.

Sent from my SAMSUNG-SM-G870A using Tapatalk

snuckols64

Thanks guys! Ok, so I followed one of the diagnostic intentions and just finished test the solenoid. With the resistor off I get full pack voltage on the battery + main side of the solenoid. When I press throttle, I get full pack voltage on th other side. When I release throttle, the voltage never drops on that side. Does that equal a bad solenoid? Basically, it’s closing on throttle push, but not opening on throttle release.

yurtle

His is a PDS from the Title, so FNR is a toggle switch, unlike a series cart.

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.

yurtle

Sounds like you tested it correctly, and sounds like a "welded" solenoid. I'm assuming the negative test lead was on pack negative?

With a solenoid always closed, whatever the minimum amperage is from controller to both sets of motor windings may account for part of the problem. Juice any time the key is on.