Cart not moving, motor seems to turn.

[Cbcwilly]

I have a 2005 EZGO PDS 36v that I bought a couple years ago. It is a lifted cart with larger tires and a rear seat. I have made some upgrades to it since I had gotten it since we use it primarily on hilly terrain and I was not happy with it's performance.
Those include, Trojan T-125 batteries, Scotty B's kit with the Alltrax DCX400PDS, Solenoid, 2 gauge cables and an LED battery meter.

The cart had been running great however the other day my wife put a bag of mulch on the back and went to drive. As soon as she encountered an incline the cart stopped. The battery meter was showing a standing reading of 38.2 with the key off. When the gas pedal is depressed the meter crashed to 24.2, the solenoid clicked and while lying under the rear of the cart, the motor makes a hum noise and in my opinion something smells weird, not burning but not normal.

I moved the cart to a level surface and turned to the site for help. Consequently, I have removed both of the rear tires and checked the hubs and the splines. One looks great, the other I have yet to get the hub off as it is being stubborn, my assumption due to not being able to remove it is that it is okay as well. All connections are clean and tight at the battery pack, the solenoid and the motor.

Would anyone have any other suggestions or experience with this issue?

Your help is appreciated in advance!

[JohnnieB]

Sounds like a battery failing under load, but it might be a bad high current connection. (What the symptoms means depends on where the DVM battery meter is connected.) Or it could be some other things.

Where is the DVM battery meter connected? Mine is connected directly to the main + & - terminals on my battery pack and stays on 100% of the time.


1. Check the F1&F2 cables for worn through insulation where they are routed around the battery frame. (see attached picture)

2. Check for any cable, connection or component getting warm or hot.

3. Check the individual battery voltages while trying to move. Each should be 1/6 of total pack voltage under load.

BTW: You can check for stripped spline just by looking at the castle nuts on the axles. If the nut is turning and the hub isn't, the splines are stripped. It only take stripped splines of one side to keep cart from moving.

What is the height of your rear tires? (Tall tires, rear seats and heavy loads don't play well together, especially on hilly terrain.)

[kogieblack]

Could be a worn hub issue.

[Cbcwilly]

Thanks for the suggestions. I'll be looking for the worn cables around the frame later today.

Tires are 22". Splines on the hubs are confirmed good. DVM Battery meter is connected direct to the main +/-.

[JohnnieB]

Since the DVM battery meter connected directly to the battery pack, dropping from 38.2V to 24.2V means:
1. A huge amount of current is being drawn.
2. Battery(ies) failing under load.
3. Excessive resistance in the cables connecting the batteries in series.

The motor is 10 years old, so the brushes may be gone.

Be careful about how far you drop the pack voltage while troubleshooting. Irreversible physical damage to the plates starts at about 1.5VPC (Volts per Cell), which is 27V for a 36V pack.

[tonyton]

I'm no specialist I this, but I have found several electric carts that have acid in contact from a battery post to the frame. I've had 3 volts running around in a frame! Personally I would fill, charge them and check the voltage, unplug and check again in an hour. I would check a negative terminal to frame to see if the acid is carryinn away current. I've seen several volts in the frame. If so, clean it ALL with baking soda. One battery goes down, it's probably bad. We have replaced 30 hubs also. The other weak link. A bad hub will let the motor run and RR tire wobble but not turn. IT also leaves a ground metal residue. It will be the right side usually. Good Luk.