48V 10kW with VEC500 controller just died!!!!

[Apcerame]

A buddy of mine has a golf cart with the 10kw motor installed controlled by a single VEC500 controller.  Just recently it started cutting off on him randomly and then completely died.

Batteries are charged at 51V and i'm reading 51V at B-/B+ and on the other side of the main fuse.  The pink lock wire has the 51V going to it as measured to B-. 

And that led me to measuring the 5V power going to the throttle.  It only reads .1V.  Also the 5V is missing at the connector going to the hall effect sensor.  That I measured from red to black. 

Any thoughts?  What else do I need to check? Thanks in advance!!!   

[Bikemad]

Hi Anthony,

If the +5V supply is only 0.1V it could be a faulty 5V regulator chip inside the controller or an external short to ground on one of the +5V wires for the throttle/Hall sensors etc.

Try disconnecting the throttle and unplugging the hall sensors to see if the 5V supply returns. If it does, this may indicate either a short circuit or a weak 5V regulator output.
Reconnect them one at a time to see how each of them affects the voltage on the +5V circuit.

If it is just a fault with the +5V regulator chip, you may be able to get the controller to work again by supplying a 5V supply from an external source.
3x AA batteries in series should work for testing, and these could be replaced by a suitable DC/DC converter for a more permanent fix if the external supply cures the problem.

Alan

[Apcerame]

Alan, that sounds awesome. 

When I was testing for 5v I had both the Hall effect and throttle unplugged.  So it sounds like I need to test with some batteries or I do have an external power supply I could use and go from there.

I’ll post again when I get that done!!!! Thanks, Anthony