97 Club car ds 48v - throttle response only at <2k from MCOR

[rodgerholl]

I have been working on my mom golf cart.
1997 48v CLub Car DS
brand new batteries
brand new soleniod
new controller (1204-410 equivalent from amazon)
New MCOR (used a conversion kit)

The cart would not move forward until the throttle was about 1/2 pressed.
No reverse.
Soleniod clicks as it should after slight movement of the GO pedal.

I measured the resistance of the throttle potentiometer at the controller. 5.5 K no throttle, Smooth transition to ~ 200 ohms at full throttle.
I checked the speed limiting resistor in the black wire on the rear microswitch and it is good. but in order to get any reverse movement, i put a 2k resistor in between the white and black wires on the micro switch. This allowed the cart to have some reverse, but still only at over half throttle

Measuring voltage at the FNR switch it is 50V with no throttle and only drops when the motor kicks in over half throttle.

The new controller has an extra large terminal (A2) that the original one did not have. (from what I read it does matter, just dont connect anything to it)
it also has a J4 4 pin connector (think that is the programmer port) and a J5 (not sure what this is for)


I think the issue could be in the controller since the inputs appear valid. 5k-0 MCOR, power to J1 Proper voltage on the large terminals.

Ideas?

Thanks in advance.

[Michael Eddie]

I have been working on my mom golf cart.
1997 48v CLub Car DS
brand new batteries
brand new soleniod
new controller (1204-410 equivalent from amazon)
New MCOR (used a conversion kit)

The cart would not move forward until the throttle was about 1/2 pressed.
No reverse.
Soleniod clicks as it should after slight movement of the GO pedal.

I measured the resistance of the throttle potentiometer at the controller. 5.5 K no throttle, Smooth transition to ~ 200 ohms at full throttle.
I checked the speed limiting resistor in the black wire on the rear microswitch and it is good. but in order to get any reverse movement, i put a 2k resistor in between the white and black wires on the micro switch. This allowed the cart to have some reverse, but still only at over half throttle

Measuring voltage at the FNR switch it is 50V with no throttle and only drops when the motor kicks in over half throttle.

The new controller has an extra large terminal (A2) that the original one did not have. (from what I read it does matter, just dont connect anything to it)
it also has a J4 4 pin connector (think that is the programmer port) and a J5 (not sure what this is for)


I think the issue could be in the controller since the inputs appear valid. 5k-0 MCOR, power to J1 Proper voltage on the large terminals.

Ideas?

Thanks in advance.

I don’t believe MCORs were around in 1997, but if I’m mistaken, please feel free to enlighten me. Could you share the wiring diagram you’re currently using?

[rodgerholl]

I used a conversion kit to replace the old potentiometer (that is not easy to find is is expensive) with a new MCOR4. its still has the microswitch for the solenoid and the 5k-0 potentiometer. came with all the connectors and brackets that fit and work.
Pretty sure it is bad programming on a china controller.

think the issue could be in the controller since the input appears valid. 5k-0 MCOR, power to J1 Proper voltage on the large terminals.
I tested the controller with an adjustable resistor in place of the mcor, the controller responded and output a very low speed at 3.9k ohms. The manual resistor allowed me to controller the speed controller through the entire range and stop, disconnect the resistor and measure the resistance (not sure that was necessary but I did it to be accurate.)

My thoughts are that the programming on the controller is off and is set to more like 4K to 0 instead of 5k to 0.
the MCOR will supply a smooth resistance change at 5 K (at 1/2 inch of pedal travel) but it tends to quickly go from 4.2 to 3 midrange (where the cart takes off) and then finishes at ~ 120ohms max pedal travel.