Throttle acting funny, motor spinning without input

[MorbidlyObeseKoala]

Small issue with testing my powertrain off of the vehicle before mounting anything. I did search for a while without finding anyone with this issue.

I have one of those cheap, generic throttles you see on ebay and amazon with the anodized grips
a sunwin brushless controller with adjustable voltage settings (48v-72v)
and a small 72v battery as the testing power supply.

I had the throttle wires plugged in and no response. Then I reset the controller with the self-learning cables connected and it seemed to cycle through a few non working configurations (buzzing, cogging, before finding one that ran smooth).

Now when I connect the throttle, it starts spinning right away. The throttle input will make it spin faster but the motor won't go back to not spinning until I kill the power to the system.

Any clues what to do next? Would loose connections cause it to behave this way?

 

[E-HP]

Now when I connect the throttle, it starts spinning right away. The throttle input will make it spin faster but the motor won't go back to not spinning until I kill the power to the system.

Any clues what to do next? Would loose connections cause it to behave this way?

Try checking the continuity of the ground wire (black throttle wire to controller ground). If it's a poor connection, the motor will run, or may run at full throttle if it's floating.

 

[amberwolf]

first make sure you disconnected the learning wires.

if they are and it still turns, then disconnect the throttle.

if it doesn't still turn, then it's a problem with the trhottle or it's wiring.

the most common is a ground wire problem as noted n the previous post.

is the throttle a potentiometer or a hall type?

the sunwin contorllers ive seen posted about usually requre a minimum of around 1.4v before they react to it. a hall type should ouptut around 0.8v at minimum. if yours is outputting more than that, a magnet might be loose inside it, and in the wrong postion, so that it causes higher voltage at rest than it should have.


if it's a potentiometer throttle, then it should have zero volts on the signal line at rest position. controllers that expect a hall throttle sometimes have troulbe with this, but not usually in a way that causes the motor to spin. usually it causes a throttle input error, making the controller be disabled until it's reset. but the cheap ones don't usually care--it just takes more movement of the throttle to get the motor started, and usually has less motion range before the mtoor reaches full speed.

if it is a pot throttle, and tje cpmtp;;er has a problem dealign with it, you can add resistors at the ends to fix it. we'll wory about that once you determine this is the issue, if it is.

 

[MorbidlyObeseKoala]

Good info here. Thanks to you both.

I'll pull it apart tonight to take a look at the connections and figure out if its a hall or pot type.

 

[amberwolf]

easy to check with a multimeter set to ohms.

throttle disconnected from controller.

red lead on signal wire, black lead on either of the other two.

turn throttle.

if rreading does not vary from a few kohm to zero or zero to a few kohm, it's a hall throttle

if it does vary like that it's a pot

 

[MorbidlyObeseKoala]

It wasn't tough to take apart the piece near the handle of the throttle (3 screws). Popped off the cover, lo and behold, the sensor was out of its little mounting spot close to the magnet on the handle; https://imgur.com/a/WmmX2aN.

The handle has 1 continuous magnet and as it turns, the magnet moves away from the sensor ever so slightly.There was a glob of hot glue in there that had detached from the other plastic and it was sort of holding everything in place. So I added a dab of super glue here and there to keep everything stationary once it was all back together.

Tested again with power, works like a dream.

Thanks for your help guys. Adding a little more knowledge about how all these things communicate together with each step.