# Curtis 1231C throttle help



## eTrike (Apr 21, 2014)

Howdy all,
I purchased a 1231C-8601 from another DIYEV user and installed it in my Zap Xebra. As far as I can tell, the throttle is the same (0-5K), and I know of one other Xebra on evalbum who installed this same controller.

My issue is that it doesn't seem to respond normally to the throttle.

It does respond once the throttle is nearly floored, but takes off like a rocket once it engages-- even when I let off the throttle(!), so I have to disengage the contactors or hit emergency kill switch to stop. 

I tried switching the throttle wires and got the same result.

The Xebra was working on the previous controller (Alltrax SPM72400-- which I think has a throttle learning ability), so perhaps potbox is suspect? IDK why it would rocket ahead even after letting go of throttle though unless the potbox is not lowering resistance normally (it seemed to respond normally on Alltrax).

I haven't found any similar stories to compare notes to, but I have the manual and will test the potbox if I can figure it out. 

EDIT: I tested the potbox and it is 5k-0, not 0-5k as I need, and the minimum value is about 95ohm, not <50 as manual states it should be. In my initial testing I didn't try flooring it to stop as that is counterintuitive, but perhaps that would have done it since it is opposite. I thought swapping the two wires on the controller would effectively inverse the pot output but I guess not. 

Any insights would be tremendously appreciated!


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## novaal (Oct 1, 2015)

I just found this old thread, you probably already figured this out already but for others looking for this info in the future I just did the same thing on a Xebra, throttle was a Curtis EFP713-0504. 

The original wires used are white and red for 5k to zero ohms, the bundle of wires coming out of the box also had black, green, brown, gray and yellow wires. The black and white wires provided the correct zero to 5k ohms for the Curtis controller.


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## eTrike (Apr 21, 2014)

Thanks for sharing!

Indeed it was that simple.. the potentiometer inside the throttle has three blades, two are used for 0-5k and the other for 5k-0. Tons of googling came up with similar questions like mine without much of a clear answer. I had ordered my first Alltrax controller from EVDrives so I called them up and spoke with Carl about ordering a pot from him. He was able to clearly describe the pot function more than hours of Googling and actually talked me out of sending him $$ for a new pot. What a great guy and company... highly recommend!


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