EZ Go TXT won't pull hills

[JohnnieB]

I suspect the brush timing is shaded more towards one direction than the other (CW or CCW) in some cart motors, maybe all of them.

I haven't had the end cap off any of my cart motors, so I don't know if there are any pins or alignment aids to precisely locate the end cap when attached to the motor housing. If not, there may be enough slop in the end caps mounting bolt holes and motor housing's threaded holes to offset the brush timing by a few degrees of rotation in either direction.

[timwc1953]

JohnnyB, I tried changing the wires on the motor and the cart runs just as before. It runs great on level ground, but will not pull a slight upgrade very well or at all if it’s steep. But again it will back up that same hill just fine. I had my voltage meter hooked up to the pack, started out 38.3 volts and would drop to around 35 volts when trying to go up a hill. On flat ground once going, it would go As low as 32 volts but that was at 22 MPH. These batteries were just bought and installed yesterday. It’s really weird how it will back up the hill when it won’t go forward up the same hill. I am thinking there is something else going on.

[JohnnieB]

Originally Posted by timwc1953

JohnnyB, I tried changing the wires on the motor and the cart runs just as before. It runs great on level ground, but will not pull a slight upgrade very well or at all if it’s steep. But again it will back up that same hill just fine. I had my voltage meter hooked up to the pack, started out 38.3 volts and would drop to around 35 volts when trying to go up a hill. On flat ground once going, it would go As low as 32 volts but that was at 22 MPH. These batteries were just bought and installed yesterday. It’s really weird how it will back up the hill when it won’t go forward up the same hill. I am thinking there is something else going on.

I'm thinking you're right,

[dundeebarnbuggy]

Clamp a meter on your battery wires to see amp draw in both directions. It might give a few clues.

[timwc1953]

I will do that. Thanks!

[timwc1953]

dundeebarnbuggy, So I finally got a chance to clamp a meter on and get amp draw on both forward and reverse on my cart when trying to pull a hill and when stalling out in forward, the amp meter read right around 100 A, and pulling that same hill in reverse it topped out over 300 A. Now on flat surface it would read better than 300 A in forward and the cart was moving really fast. For some reason it just does not have low end torque in forward, but does in reverse.

[dundeebarnbuggy]

Ok, I think. Trying to decipher your post and I seems your motor is drawing 100 amps uphill forwards, 300 amps in reverse. On the flat, what does it draw forwards once at speed?

[timwc1953]

At top speed on flat surface it draws a little over 300 amps, which I don’t understand. It just seems to be a low end torque problem. The controller was just rebuilt recently or I would suspect that. The cart will really fly on flat surfaces, topping out at 22+ MPH. Again it just have the muscle to pull a slightly steep hill in forward but will in reverse.

[Volt_Ampere]

That's a high current draw for top speed on level pavement. My cart pulls 70 amps at 24mph. (Battery at about 53V) If it's pulling that much current at speed, it makes sense that it will struggle on hills.

[dundeebarnbuggy]

Shot in the dark here. No chance that the brakes are dragging in forward and don't hinder movement in reverse? Either due to axle torsion difference in forward vs reverse or someone setting them up wrong in the first place? It would be a simple [and cheap] solution to your problem.