Speed dropping out at 15mph

[Scooter1960]

Originally Posted by InvalidUsername

I got a DC amp clamp meter like this with a frequency counter at Lowes or Home Depot for $100 in case you're in the market for a better meter

Thanks Invalid. I have seen these before and probably a good thing to invest in and learn how to use.

[InvalidUsername]

Originally Posted by Scooter1960

Thanks Invalid. I have seen these before and probably a good thing to invest in and learn how to use.

Shop around. I think you can get them cheaper on Amazon/Ebay. I was just in a hurry and payed more than I could have

[Scooter1960]

Ok, so I did a couple more things and wanted to wrap up this post for now. Im good with the 17mph that I am getting with the speed magnet (and yes, I am getting 2mph more with a controller set at 15mph).
I went ahead and threw my “known good” MCOR” from my onward into the problem child black precedent. Nothing changed so issue is not with MCOR.
Next, I got to thinking, “what if it’s the new lithium battery”? So, I lifted to battery out of the black precedent and set it on top of my Onward lithium. Hooked it up with some cable extensions and…..cart (Onward) ran fine at 19mph with no drop out of speed. 19mph is top speed for the onward with Curtis controller programmed with speed code 4.
Lastly, for grins, I hooked multi meter to light green wire from 16pin at controller and voltage was 5.0 sitting still and 2.4 while driving until speed dropped out at 19mph. Here is a link to google drive video. Not real exciting, just shows what I talk about above.

https://drive.google.com/file/d/1zLd...w?usp=drivesdk

So, to sum it up, I think the problem is with the controllers. At this point I do not have a “known good” Curtis controller to test with and do not want to spend the money on shop diagnostics. I will probably save up for a handheld and/or look around for a known good controller with speed code 4 and try again.
For now, she is running good at 17mph with the new lithium battery. This is with a controller that is programmed at 15mph and has a speed magnet installed (Excel cart with ADC motor). I think I saw somewhere in this thread that speed magnets don’t work on Excel carts…….speed magnet is working on my Excel cart.
That’s all for now. Even there was no solid resolution to my speed drop out issue, hopefully my journey will help others who might be encountering similar issues. I learned quite a bit from questions and answers here and appreciate all the help as always. Hope everyone has a good weekend!!!!!

[InvalidUsername]

The drop to 2.4V is interesting and kind of what I was looking for. 5V sitting still becomes 2.5V pulsing at 50% duty cycle. At a certain frequency/speed the voltage goes down slightly, which suggests an increase in resistance, which a frequency higher than at 0-15 mph (17 with speed magnet) conceivably could be causing. It's consistent. 2.4V could be below what the controller considers legitimate pulses, triggering a motor stall fault which cuts off armature current until it sees pulses again.

If the cart cuts out at a consistent frequency, then that would nail it.

If speed magnet is working then maybe the Excel parameter in the controller is turned off. Do you have regen at low speeds, like below 10mph?

If you have a laptop to run the 1314 software, instead of buying a handheld make a DIY 1309 cable for around $20-30 and you will be able to do more than with a handheld.

btw it's not the controller IMO

[Scooter1960]

Lots of life stuff coming up right now so the fact that cart is running well at a speed I’m ok with is good for now. However, can I ask, when you say you think it’s not the controller, what do you think it is? Are we back to speed sensor or something else? I know I am going in circles without the DIY Laptop reader or Handheld but just curious if you had a guess based on the speed dropping out at certain frequencies?
I’m a little confused because your post seems to mention a couple things related to controller (“If the cart cuts out at a consistent frequency, then that would nail it”) but then you say you don’t think it’s the controller. Anything else I could throw at it or do (short of checking with laptop reader or handheld) that might cause a change in controller behavior?
To answer your question, I do not have regen at any speed with the magnet in. Would have to remove the magnet to see if regen was there below 10mph.
Thanks again. I’m willing to try one or 2 more easy things before I button it back up and call it good for now.

[InvalidUsername]

You said you tried 2 different controllers with the same results, so I think is next to impossible for 2 controllers, one a Curtis and one a Chinese clone, to be having the same unusual/rare problem.

My working hypothesis is that there is something funky going on in the wiring between the speed sensor and the controller that causes the circuit resistance/impedance to increase at the speed pulse frequency above 15 mph (or 17 mph with high speed magnet), which causes the input voltage to drop below the threshold the controller is programmed to recognize as valid. The controller says 'uh-oh no speed pulses', faults and shuts off the motor. Your video appears to bear that out when the motor shuts off at 2.4V (which actually could be 2.35V due to meter resolution). The voltage could actually be much lower than 2.4V, but due to meter sampling rate and lag you don't see it. We won't definitively know until we can see what the frequency is doing at 15mph and above.

But frankly 17mph is good enough for a spare cart, right? If you run into someone with a frequency counter on their DVM it would be easy and worthwhile to measure it. Just put the dial on Hz and measure the green wire like you did for volts.

An easy thing you can do before you shut the lid on the case is spend some time examining the 3 speed sensor wires to see if you can notice anything unusual or out of the ordinary, like excessively bent wires, broken wire, missing insulation. Particularly look for corroded/loose/bent connector pins. All 3 sensor wires go directly to the controller 16-pin connector

[Scooter1960]

Thanks and yes….Im good with 17mph for now on the spare cart. Later on, as time allows, I can get back into it and check ohms with meter and possibly build the laptop reader (or have my son in law build it). I will check physical speed sensor wiring before putting everything back together.
Thanks again for all your help. I’ll come back here and post if and when I re-open the investigation 🛺. Might post a picture of it put back together….showing the installed battery and Bluetooth SOC meter which is kind of cool