RXV wheels locked up while driving

[magnmac]

Hi guys, my 2013 RXV ex-fleet cart has been working perfectly for several golf outings after fixing the throttle no return issue, until a few days ago. On the third hole while driving at about half speed the rear wheels just locked up. I thought the worst, but I just turned the key from F to off, then back and it worked fine. It worked flawlessly for the next 2 hours. No smells detected.

I thought it might be a loose cable as I know it will engage the brake if no battery is detected, but all are tight. After charging it all US batteries are at 12.6 V each; so now I am thinking maybe the solenoid is going? or might it be the key switch? it always seemed like it has too much play in it.

I am just hoping I am not stranded in the middle of a good round, or travelling down the pavement road at 19 mph and having it happen blowing the brake out!

any ideas?

[magnmac]

bump?

[sltintexas]

when people have issues with their brakes, i just always assume their motor brake isgoing out.

[magnmac]

I never did replace the brake when this issue happened last year. I have done over 100 rounds of golf since without this issue reoccurring until today. It locked up again, 300 feet from fully charged on smooth pavement. This time key switching did not help unlock the brake. No brake smell. Still locked up when tow switch toggled. I reconnected the wires as instructed under the cover to move it to a better location, the brake released, then connected the wires back up, and just for fun tried to run the cart and it was fine. I drove it back home.

So now I am wondering if I should just use it like before? I still don't know what caused the brake to lock up just once last year; All batteries are at 13.0-13.1 volts. All wires look good; no visible corrosion.

I am thinking of just removing the brake and taking it apart and inspecting/cleaning it, or should I just replace it: the cart has 5 years on it now.

[jkredman]

The brake is held open by the controller. Check your wiring, toward the back of the cart, for loose connections or corrosion; especially in the connector. Pull the plastic wrapping and look at the individual wires. Some early model harnesses had some hidden splices in them (as I understand it.). Anything the interrupts the voltage to the brake, will cause it to set.

Also put an ohm meter on the pins into the brake. It should measure around 25.5 ohm. Much higher or much lower, and the controller will. Throw an error.


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[magnmac]

All wires look good. I am not sure if 2013 qualifies as an early model, but they look fine. I didn't pull the large wraps off the middles of the main cable sets from the motor etc; the ends of the wires are exposed and are corrosion free.

I took apart the brake; looked good. A tiny bit of dust on a few of the pieces; not much corrosion at all. Friction material looks barely worn. I cleaned it, put it back together, put it back on, tightened to spec, and it "still" works fine. Measured at 28.3 ohms. According to a post by BobBoyce that is the upper limit of spec:

Originally Posted by BobBoyce

Welcome to the forum, and welcome to the most common problem that plagues the RXV.

On of the first things to check on the RXV is the battery pack voltage. Are the batteries fully charged? The RXV controllers are very finicky about proper voltage. To properly test some things, you will need a multimeter. One with a digital readout is preferred.

If the brake does not disengage when you follow the Emergency Tow Mode by swapping plugs under the controller cover, then it would seem that either you do not have voltage at those connections, or the motor brake itself is bad. The first thing to check after confirming that the batteries are properly charged would be to check the blade fuses under the caps attached to the controller cover. 2013 RXVs should have 2 fuseholders there, one with 2 red wires and the other with 2 yellow wires. If either of those are blown, replace with a new fuse of the same value. If all is good at this point, it's time to test the motor brake.

Unplug the 2 pin connector at the motor brake. It is located at the top of the rear end of the motor. You hold the retaining clip of the harness plug slightly away from the socket and pull upon the plug. It has a weather seal, so it will be a bit firm. Once this is done, try activating Emergency Tow Mode again and check with your meter to confirm that you have batter pack voltage at the 2 pins of that motor brake plug.

If you have pack voltage there, then it's possible that the motor brake itself is faulty. You would use a low ohms range on your multimeter to check the motor brake coil by putting the meter probes in contact with the 2 pins of the motor brake socket. You should read between 25 to 28 ohms. If it is open circuit or shorted, replace the motor brake unit. You can find them listed on eBay for much less than from E-Z-GO. It's a good idea for all RXV owners to keep a known good motor brake on hand for that time that it will fail.

If you have no pack voltage there, then you'll need to trace back through the Run Plug (9 pin connector under the bottom of the cupholder assembly), the Brake Switch (under the floor mat and pedal cover), and the wiring in between the battery pack and the motor brake plug itself.

RXVs are notorious for having bad connections in the harness, at the places where wires are bonded together, and at the terminals of plugs and sockets.

At this stage, you would probably need to obtain the wiring diagram. We can help if you need further assistance. Where are you located?

Bob

so I am back to thinking what I thought last year; solenoid? Can they be temperamental?

Edit: by the way, checking with the local EZGO dealer they want $300 CDN for the **** brake.... should I order one looks like I will have it sent to the mailbox and pick it up for $115 US

[BobBoyce]

Originally Posted by magnmac

All wires look good. I am not sure if 2013 qualifies as an early model, but they look fine. I didn't pull the large wraps off the middles of the main cable sets from the motor etc; the ends of the wires are exposed and are corrosion free.

I took apart the brake; looked good. A tiny bit of dust on a few of the pieces; not much corrosion at all. Friction material looks barely worn. I cleaned it, put it back together, put it back on, tightened to spec, and it "still" works fine. Measured at 28.3 ohms. According to a post by BobBoyce that is the upper limit of spec:




so I am back to thinking what I thought last year; solenoid? Can they be temperamental?

Edit: by the way, checking with the local EZGO dealer they want $300 CDN for the **** brake.... should I order one looks like I will have it sent to the mailbox and pick it up for $115 US

Looks like they are back in stock...

https://www.ebay.com/itm/301992451277

It'll be good to have a spare at that price. Even if yours is good now, it will likely fail at a most inopportune time.

Try going through all of your power connections in the motor brake chain... Unplug and replug each connector multiple times. Start at the fuseholders and the brake bypass plugs/sockets under the controller cover. The run plug and socket. The brake switch. And the motor brake plug/socket.

Bob

[magnmac]

Originally Posted by BobBoyce

Looks like they are back in stock...

https://www.ebay.com/itm/301992451277

It'll be good to have a spare at that price. Even if yours is good now, it will likely fail at a most inopportune time.

Try going through all of your power connections in the motor brake chain... Unplug and replug each connector multiple times. Start at the fuseholders and the brake bypass plugs/sockets under the controller cover. The run plug and socket. The brake switch. And the motor brake plug/socket.

Bob

Thanks for your input Bob, will do. Is some sort of conductive grease a good idea for the connections?

Are the "newer" thrombetta solenoids pretty robust now? Or should I have a spare one on standby also? I recall reading somewhere that most replace it everytime they do replace a brake.

Edit: Actually it states it right in the brake ad:


6" MOTOR BRAKE ASSEMBLY
This innovative Motor Brake is an OEM (Original Equipment Manufacturer) replacement motor manufactured for installation on E-Z-GO RXV Electric Vehicles. The motor brake helps to slow the vehicle when the driver pulls his/her foot off the accelerator pedal. This motor is manufactured with an enclosed fan-cooled and open drip-proof design. This replaces Item# 605867



Item # 610065

Used on 2008-current E-Z-GO Electric RXV Vehicles
Enables the vehicle to slow down when the accelerator pedal is released
Weight: 13 lbs, Measures: 6"; Voltage: 48 VDC
(1) Motor Brake included in this auction
It is recommended to change both the solenoid and the electric motor brake at the same time. See our other auctions for RXV parts.
Pictures of carts are for vehicle reference, they are not included with this auction.

[rngilliland]

Originally Posted by magnmac

Is some sort of conductive grease a good idea for the connections?

Grease isn't needed, but if you use some be sure and use dielectric grease. It is NOT conductive.

[BobBoyce]

If your RXV still has the light duty solenoid, I would certainly replace it with a new Trombetta solenoid. Since you have a 2013, be abolutely sure to buy the 36V one, not the 48V one. Here is why...

The controllers prior to mid-2014 had a main coil (solenoid) PWM value of 75% (36 VDC).
That includes controllers 1206AC-5201, 1206AC-5202, 1206AC-5203, and 1206AC-5350.

The controllers post mid-2014 had a main coil (solenoid) PWM value of 100% (48 VDC).
That includes controllers 1206AC-5211, 1206AC-5212, 1206AC-5213, and 1206AC-5360.

Bob