ez-go rxv is super slow

[Red neck cart tech]

the rxv im working on has good battery voltage but is super slow in each direction and will barley move. it has 45 volts under a load. how do I check the speed sensor or throttle position sensor without a scanner

[cgtech]

45v at low speeds is horrible, sounds like bad batteries has the controller in "limp-home-mode".

[Red neck cart tech]

The 45 volts is under a heavy load and the car should run correctly down to about 42.5

[jeremy98]

Originally Posted by Red neck cart tech

The 45 volts is under a heavy load and the car should run correctly down to about 42.5

When the cart starts to run the voltage down this low, it will cause the motor to pull more amperage to operate. I agree with CGTECH regarding the batteries and how low they are. Normally a good set of batteries should not drop any more than 2 volts when under load. Do you know which control is installed in this cart, Danaher or Curtis?

[Red neck cart tech]

danaher it is a 2009

[Red neck cart tech]

I am bringing the batteries up now not sure about the limp home mode it is so slow it would take 10 minutes to go 100 feet I will post my findings

[BobBoyce]

Originally Posted by Red neck cart tech

I am bringing the batteries up now not sure about the limp home mode it is so slow it would take 10 minutes to go 100 feet I will post my findings

Check the motor speed encoder (likely an encoder bearing in 2009) for a bad connection at the plug, or use a scope to test both signal wires for square wave pulses when the motor is running. Put the rear axle up on jack stands first of course. If that checks out, then measure the resistance of the motor temperature sensor at the 2 wire connector when it is unplugged from the harness. Those 2 sensors produce a crawl rate speed response from the controller.

Bob

[Red neck cart tech]

thanks Bob do you know what the ohm readings of the temp sensor are supposed to be ? I have good voltage now but still crawling, also I removed the plastic cover on the motor at the cables and I smell smoked electrical, I am about to test the motor ohms readings as well

[Red neck cart tech]

Bob I have a advanced troubleshooting booklet from ez-go customer car and it has a picture of the encoder as a small oval unit mounted to the drive end of the motor opposite end from the brake but this 2009 car does not have one ??

[BobBoyce]

That's why I said 2009 should have the bearing encoder. It is part of one of the motor bearings. The cable for it comes out of the motor and has a 4 wire connector. 2 of those wires are the + and - 5 volt power leads. The other 2 are signal A and signal B. They are 5 volt square wave pulses, referenced to the black (-) wire. Both signals must be there in order not to get an error. You'll have to remove and disassemble the motor in order to change out the bearing encoder. I was told the replacement costs about $180.

Not sure on the temperature sensor value. I think it is a thermister imbedded into the motor windings to measure the motor internal temperature.