Strange hill behavior

[Fallamaihn]

Just picked up a 1990 electric EZ-GO. I read through all the stickies in this forum, which is an amazing amount of info. I will definitely upgrade my DMM and get to work on some diagnostics, but I thought I'd post the main issue I'm having to see if anyone can help me narrow down the cause.

The problem:
Our neighborhood is quite hilly. Generally the cart makes it up all the hills but verrrrrry slowly. But sometimes it stops altogether. right at the start. Continuing to push the throttle then makes the cart actively drive in reverse (not just roll), even though the selector is still in F. When I get to flatter ground, release the throttle and re-engage, the cart will then start to slowly ascend. At some point it feels like something kicks in and then it has more power and putters up the hill like normal.

The cart:
Batteries are brand new, and I just replaced all the battery cables, as they were quite corroded. The rest of the wiring looks like it's seen better days, so I'll definitely need to go through some of that. Possibly related, but when I push the throttle down all the way the power cuts out completely. I have to find a sweet spot at like 2/3.

Based on this, I'm just wondering if I should focus on the F-R switch, the solenoid, the throttle, something else?

[cgtech]

Unplug controller terminals 2 & 3 (small wires). Probe the wires, with your meter set to the "20k ohms" setting. At rest should be reading around 0.15, as the throttle is pressed, reading should go up to around 5.00, but shouldn't exceed 6.00. If your throttle values are out of range, it can almost always be adjusted.

[Fallamaihn]

Originally Posted by cgtech

Unplug controller terminals 2 & 3 (small wires). Probe the wires, with your meter set to the "20k ohms" setting. At rest should be reading around 0.15, as the throttle is pressed, reading should go up to around 5.00, but shouldn't exceed 6.00. If your throttle values are out of range, it can almost always be adjusted.

I have a DMM, so it just auto-ranges for absolute readout. At rest the readout is basically zero, full continuity. At full throttle it ramps up to about 7 kOhm.

I also measured the voltage across the battery and at the speed controller at different throttle positions. Battery voltage appears normal depending on load and hill angle. Speed controller voltage always drops to zero when I go above a certain throttle position.

[cgtech]

7k is too high, and would cause "high pedal disable", because the throttle is out of range, above 100%.

Needs to be adjusted down to about 5.5k max, this can be done at the throttle potentiometer. It's a very touchy adjustment, a little bit goes a long way.

[Fallamaihn]

Thanks for the info. Is there a good guide for adjusting the potentiometer? I searched around and didn't find anything clear. I looked at the cart itself and couldn't figure out exactly where to make an adjustment.