EZGO RXV motor?? Dragging

[drewbaby88]

So I mess around with cart repair in my spare time. Had a guy bring me an RXV 48v cart the other day. He told me it sounded like it was grinding and would stop suddenly and violently sometimes. I was convinced it was the motor brake. Pulled the brake off and ohm tested it at 26.8 ohms.

I am getting no voltage at the two-pin wires going into the brake.

The cart will still drive now at pretty good speed but it sounds exactly the same. It sounds like metal grinding.

Is it the motor? Bearing encoder?

I’m not sure of the year but it’s SN#5031340

[rockfordpi]

Originally Posted by drewbaby88

So I mess around with cart repair in my spare time. Had a guy bring me an RXV 48v cart the other day. He told me it sounded like it was grinding and would stop suddenly and violently sometimes. I was convinced it was the motor brake. Pulled the brake off and ohm tested it at 26.8 ohms.

I am getting no voltage at the two-pin wires going into the brake.

The cart will still drive now at pretty good speed but it sounds exactly the same. It sounds like metal grinding.

Is it the motor? Bearing encoder?

I’m not sure of the year but it’s SN#5031340

The first thing you need to find out is the year. Google or search BGW to find out how to find year model and post same and you will get lots of help from there.

[Chevota Guy]

Can't help with the grinding, but here's how to read the year on an RXV. On the outside of the frame in the front, under the splash shield, there is a label with both the S/N and Mfg date code. It can be seen by looking in over the top of the drivers side front tire.

As far as the no voltage condition, my understanding is that the brake has to have voltage to release, so one shouldn't able to drive it with no voltage to the motor brake.. Possibly the motor brake making that racket?

The date code letter is the month D=April. Next two digits=day. Last two digits =year.

[cgtech]

Violent jerking & stopping is almost always encoder or its wires.

[drewbaby88]

The cart is a 2009

I have also found that the run/tow switch is failing. Have to fiddle with it to get to go back into “RUN”.

The cart will move like normal but sounds like I’m holding the brakes the entire time. It will still stop with the motor brake removed. If I turn the key off, it will not disengage the brake in Tow mode.

[cgtech]

Brake dragging is totally different symptom than violent jerking & stopping.

[drewbaby88]

Originally Posted by cgtech

Brake dragging is totally different symptom than violent jerking & stopping.

Right. I didn’t make that very clear. The owner told me that was the symptoms. It feels like to me I’m riding the brake.

With the motor brake off it still stops if the key is on. It will not coast at all. I understand it to be a regen motor. Could that be failing?

[drewbaby88]

Bump

[cgtech]

The motor isnt a "regen motor" in the traditional terminology people use that phrase in (describing a DC Seperately Excited motor). The motor in RXV is a 3-phase AC motor. It does heavily use "regenerative braking". I have been working on RXVs since 2009 and have seen only one motor failed (not counting failed temperature sensors), and it failed due to corrosion/acid intrusion.

[drewbaby88]

Originally Posted by cgtech

The motor isnt a "regen motor" in the traditional terminology people use that phrase in (describing a DC Seperately Excited motor). The motor in RXV is a 3-phase AC motor. It does heavily use "regenerative braking". I have been working on RXVs since 2009 and have seen only one motor failed (not counting failed temperature sensors), and it failed due to corrosion/acid intrusion.

So how do I diagnose what’s going on with this cart? What all should I check?
1) No brakes if key is off
2) cart stops while driving but pulses if stopped on a decline
3) cart drives full speed but sounds like brakes dragging
4) cart never stops abruptly/ motor brake ohms are 26.8
5) Run/Tow Switch is failing. Hard to get it back to “run”