Speed sensor bad?

[Conradconrad]

So I got the new XCT controller back in, and hooked up the solenoid(correctly).

And now I have a new issue. I can not go over 10mph but I drove with the laptop connected and realized that there is no speed(rpm) values being shown, therefore my speed sensor is the issue.

I have the PDS type 1 speed sensor with the white plug with a black, red, and white wire.

I checked the connection at the plug for any loose wires and all look good. I traced the wire back to the motor and there is no insulation wear.

Is there a way that the speed sensor broke with the cart parked in the garage for two weeks, lol?

Is there a way to test it?

[JohnnieB]

On the Controller Settings page, make sure the Speed Limit Enable box is checked.

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With speed sensor plug plugged into XCT, measure from Black wire (negative) to Red wire (Positive). Ought to be 12V to 15V or so.

If it is good, lift rear tires off ground and measure between Black wire and white wire while turning tires very slowly. You to see 5V pulses as motor turns.

With stock gears, motor turns 12.44 times every time tires turn once and speed sensor puts out 4 pulses for each motor revolution, so turning tires at 1RPM slowly will produce about 50PPM, or about one pulse per second. (Speed sensors with 4 pole magnets put out 2 pulses per revolution)

That test came from a 1206MX checklist. I'm pretty sure slowly pushing cart with tires on ground will produce same results.

[scottyb]

Also make sure that 8 pole is selected for the stock motor sensor.

[Conradconrad]

Originally Posted by JohnnieB

On the Controller Settings page, make sure the Speed Limit Enable box is checked.

-------
With speed sensor plug plugged into XCT, measure from Black wire (negative) to Red wire (Positive). Ought to be 12V to 15V or so.

If it is good, lift rear tires off ground and measure between Black wire and white wire while turning tires very slowly. You to see 5V pulses as motor turns.

With stock gears, motor turns 12.44 times every time tires turn once and speed sensor puts out 4 pulses for each motor revolution, so turning tires at 1RPM slowly will produce about 50PPM, or about one pulse per second. (Speed sensors with 4 pole magnets put out 2 pulses per revolution)

That test came from a 1206MX checklist. I'm pretty sure slowly pushing cart with tires on ground will produce same results.

Speed limit Enable is checked along with 8 pole for the sensor.

I measured the voltage with the cart key on in forward but did not press the pedal. Just sitting it seems to be reading about 40v, is that odd?

I did put in the new XCT controller and go for a test ride right away forgetting to load the correct field map and ran it on the stock alltrax out of the box field map.

My motor is a custom EMP motor which is a upgraded D&D motor -
170-505-0001A-LR. I obviously have a few specific field maps to run for this motor. Could running the stock alltrax field map have killed the speed sensor?

[JohnnieB]

Originally Posted by Conradconrad

1. Speed limit Enable is checked along with 8 pole for the sensor.

2. I measured the voltage with the cart key on in forward but did not press the pedal. Just sitting it seems to be reading about 40v, is that odd?

3. I did put in the new XCT controller and go for a test ride right away forgetting to load the correct field map and ran it on the stock alltrax out of the box field map.

4. My motor is a custom EMP motor which is a upgraded D&D motor -
170-505-0001A-LR. I obviously have a few specific field maps to run for this motor. Could running the stock alltrax field map have killed the speed sensor?

1. Even if the wrong number of poles is chosen, there will still be a RPM. It'll just be the wrong number

2. That is odd. You are talking about the voltage between the red and black wires on the speed sensor plug, right? Attached are the specs on the speed sensor D&D uses on their motors and I doubt if EMP changed or modified it in any way when the did their magic. Looks like voltage range is 14.5V to +24V, so 40V is mighty high. I'd call Alltrax about it.

3. Patience is a virtue. Motor might not have performed very well and might have gotten hot, but that's it.

4. Running the wrong field map wouldn't have harmed the speed sensor, however the controller applying 40V to it might have taken it out.

[yurtle]

Is 40 volts while sensor is connected?

[Conradconrad]

Maybe I did it incorrectly and maybe my technique needs work. I took a paper clip and made two L shaped piece and pushed them into the red and black ends where the wires and white connect meet. I used alligator clips to attach them to the multimeter. With the speed sensor connected at the controller, I turned the key to the on position and selected forward. The reading is instantly a -40.0v which would seem like 1) very high so that speed sensor and 2) polarity is reversed?

I tested several other batteries, my battery pack and a few other home outlets to make sure the multimeter isn’t bad.

Is my next step to unplug the speed sensor from the controller and check the controller output at the first and third pins to see if the controller is putting out the -40.0v?

[Conradconrad]

Originally Posted by yurtle

Is 40 volts while sensor is connected?

Yes it is, And with the cart on

[JohnnieB]

Originally Posted by Conradconrad

1. Maybe I did it incorrectly and maybe my technique needs work. I took a paper clip and made two L shaped piece and pushed them into the red and black ends where the wires and white connect meet. I used alligator clips to attach them to the multimeter.

2. With the speed sensor connected at the controller, I turned the key to the on position and selected forward. The reading is instantly a -40.0v which would seem like 1) very high so that speed sensor and 2) polarity is reversed?

3. I tested several other batteries, my battery pack and a few other home outlets to make sure the multimeter isn’t bad.

4. Is my next step to unplug the speed sensor from the controller and check the controller output at the first and third pins to see if the controller is putting out the -40.0v?

1. I avoid using "L" shaped pieces of paper clips to avoid them touching each other. (Yes, I found out the hard way. But that was ages ago. ) Since then I've used straight pieces of paper clips or insulated solid copper hook-up wire, or test leads with very thin test pins. Whatever work for you, just don't let them touch.

2. With an XCT or stock PDS, the speed sensor ought to be powered whenever the Run/Tow is in Run, regardless of the positions of the F/R and Key switches. Remember, the walkaway safety sounds the beeper and turns on the regen braking to keep the cart from rolling away from you, except when in Tow, and motor RPM is what triggers it, so the speed sensor is powered except when in Tow.

3. Did you also verify the test lead polarity? Also, if it is an auto-ranging DVM, take a close look at the display to be sure it is in fact, 40.0v rather than 40.0mV. I've been caught by that one a few times.

4. That's the next step. Then contact Alltrax.

[Conradconrad]

1. I avoid using "L" shaped pieces of paper clips to avoid them touching each other. (Yes, I found out the hard way. But that was ages ago. ) Since then I've used straight pieces of paper clips or insulated solid copper hook-up wire, or test leads with very thin test pins. Whatever work for you, just don't let them touch.

I like the solid copper hook up wire idea, although I might look online for some thing test pins.

2. With an XCT or stock PDS, the speed sensor ought to be powered whenever the Run/Tow is in Run, regardless of the positions of the F/R and Key switches. Remember, the walkaway safety sounds the beeper and turns on the regen braking to keep the cart from rolling away from you, except when in Tow, and motor RPM is what triggers it, so the speed sensor is powered except when in Tow.

I think my beeper has been removed(previous owner). Interesting you say the sensor is powered all times except tow. Mine I noticed is completely at 0 until the key switch is turned

3. Did you also verify the test lead polarity? Also, if it is an auto-ranging DVM, take a close look at the display to be sure it is in fact, 40.0v rather than 40.0mV. I've been caught by that one a few times.

I read you mentioned it will be between 10v to 15V usually. I put the meter on 20 VDC and the reading showed the "-1" which I know is value too large, switched to 200VDC and then it showed -40.0V

4. That's the next step. Then contact Alltrax.
I think you are right, thank you