Yiyun yk31c controller going full voltage to motor w/ no input

[Quinc]

Has anyone seen the yiyun yk31c controller going full voltage to motor with no input from the throttle before?

The first time: Been riding the razor for two days and all of a sudden it went full voltage to motor as soon as i turned it on. Had to pull a cable off a battery to get it to stop. to troubleshoot I unhooked everything but the motor and batteries and it still goes full throttle. I pulled the controller apart and there is no black/fried spots or smells.

Second time with a new yk31c controller
Rode the gokart for about an hour. Plugged it in the next day to charge and as soon as I plugged it in, it went full throttle again.. Doesn't matter if everything else is unplugged she still goes.. Wondering if it could be my power switch or possibly something else? This is the first time I have ran an LCD volt meter off the controller.


500w unite motor
36v 10ah batteries
12ga wiring

 

[amberwolf]

if it's brushed then blown fets would usually fail shorted, causing full power anytime system is powered on.

unfortunatley most of the cheap brushed controllers don't seem to have current limiting, so they'll try to put out whatever the motor asks for, which blows fets when the contorller can't really do it.

http://ebikes.ca has troubleshooting page with how to test fets

 

[Quinc]

if it's brushed then blown fets would usually fail shorted, causing full power anytime system is powered on.

unfortunatley most of the cheap brushed controllers don't seem to have current limiting, so they'll try to put out whatever the motor asks for, which blows fets when the contorller can't really do it.

http://ebikes.ca has troubleshooting page with how to test fets

Thank you for that link! A lot of good info.

Going to remove the lcd meter, on/off switch, and brake to see if that changes anything on the next controller. Also would adding a fuse anywhere specific help? It is a 28amp controller and I am running a 35amp fuse between batteries.