yet another controller voltage question

[rbridges]

I've read a lot of posts, and it's actually helped me eliminate a lot of stuff. 36V TXT. The controller is a curtis 25864G05.

I get a click with the solenoid, but the cart will not move at all. I swapped the solenoid, but it obviously wasn't the only issue (if it was at all). I jumped the motor with a battery charger, and it works fine.

Getting pack voltage at solenoid.

I ran some voltages off the controller.
M-->B- -2.06V to 0.4 when solenoid clicks and then drops to 0.0V
M-->B+ 0V to pack voltage at click (I'm getting 38.07V) and drops to 37.86V when pedal fully depressed
B- --> B+ 0V to 37.86V at click but doesn't change any when pedal fully depressed.

I ran voltages from the ITX to the 6 pin molex and they all seem to be fine.

I did check the FNR switch with the multimeter. In forward, I can get continuity with 4--8 but not 3--5. In reverse continuity with 3--8 but not 4--5.

Can anyone make sense of this? I'm thinking controller, but that's a $250+ gamble. I want to be sure. FNR switch is other thought.

[JohnnieB]

Originally Posted by rbridges

I've read a lot of posts, and it's actually helped me eliminate a lot of stuff. 36V TXT. The controller is a curtis 25864G05.

I get a click with the solenoid, but the cart will not move at all. I swapped the solenoid, but it obviously wasn't the only issue (if it was at all). I jumped the motor with a battery charger, and it works fine.

Getting pack voltage at solenoid.

I ran some voltages off the controller.
M-->B- -2.06V to 0.4 when solenoid clicks and then drops to 0.0V
M-->B+ 0V to pack voltage at click (I'm getting 38.07V) and drops to 37.86V when pedal fully depressed
B- --> B+ 0V to 37.86V at click but doesn't change any when pedal fully depressed.

I ran voltages from the ITX to the 6 pin molex and they all seem to be fine.

I did check the FNR switch with the multimeter. In forward, I can get continuity with 4--8 but not 3--5. In reverse continuity with 3--8 but not 4--5.

Can anyone make sense of this? I'm thinking controller, but that's a $250+ gamble. I want to be sure. FNR switch is other thought.

B- to M- ought to be full battery pack voltage when pedal is pushed just far enough to make solenoid click.

You don't have it and the most likely suspect is the F/R switch.

[rbridges]

Originally Posted by JohnnieB

B- to M- ought to be full battery pack voltage when pedal is pushed just far enough to make solenoid click.

You don't have it and the most likely suspect is the F/R switch.

What about the other voltages at the controller? Aren't they incorrect? My wife did complain that switching to reverse was difficult a few days earlier, but it simply stopped working when she stopped to take a picture. Never turned it off or moved the f/r switch. We also smelled a burning that seemed to come from under the seat.

[JohnnieB]

Originally Posted by rbridges

What about the other voltages at the controller? Aren't they incorrect? My wife did complain that switching to reverse was difficult a few days earlier, but it simply stopped working when she stopped to take a picture. Never turned it off or moved the f/r switch. We also smelled a burning that seemed to come from under the seat.

Yes & No or Maybe.

M- to B+ is the reciprocal of B- to M- as far as how the voltage ought to react to the pedal, but less useful for troubleshooting.

B- to B+ is more or less normal, but ought to be full battery pack voltage after solenoid clicks and a few volts less than pack voltage before solenoid clicks if a precharge resistor is installed.

B- to M- is the most significant voltage reading made, so I addressed it first.

The added info about the F/R getting harder to operate and the sizzling sounds are additional indicators of a failing/failed F/R assembly.

[rbridges]

Originally Posted by JohnnieB

Yes & No or Maybe.

M- to B+ is the reciprocal of B- to M- as far as how the voltage ought to react to the pedal, but less useful for troubleshooting.

B- to B+ is more or less normal, but ought to be full battery pack voltage after solenoid clicks and a few volts less than pack voltage before solenoid clicks if a precharge resistor is installed.

B- to M- is the most significant voltage reading made, so I addressed it first.

The added info about the F/R getting harder to operate and the sizzling sounds are additional indicators of a failing/failed F/R assembly.

Appreciate the help. The F/R turns easily now, but I can't get the continuity tests to work 100%. I read somewhere on this forum that the F/R continuity tests needed to pass 100% on both sets of contacts or it flat out doesn't work. So, I'm going to order a new F/R switch.

Thanks again!

[JohnnieB]

Mark the position of the original mounting bracket. Still may need to adjust a bit so the cam rotates into both F and R mechanical stops, but original position is a good starting point.

[kernal]

The mechanical F/R switch is a weak point in a "series" cart. Installation and adjustment is critical. If it is easy to turn, failure is imminent.
If it is adjusted right, it will be hard to rotate. A common solution is a "caddy shifter".

[JohnnieB]

Originally Posted by kernal

The mechanical F/R switch is a weak point in a "series" cart. Installation and adjustment is critical. If it is easy to turn, failure is imminent.
If it is adjusted right, it will be hard to rotate. A common solution is a "caddy shifter".

Another solution is a reversing contactor, which makes switching directions a simple matter of flipping an electrical switch.

[kernal]

yes, or that

[rbridges]

Originally Posted by kernal

The mechanical F/R switch is a weak point in a "series" cart. Installation and adjustment is critical. If it is easy to turn, failure is imminent.
If it is adjusted right, it will be hard to rotate. A common solution is a "caddy shifter".

Well, that makes me feel a little better about the diagnosis. Hard to rotate wouldn't be how I'd describe it. Never paid attention, but it's not difficult at all.