Club Car Precedent "open armature" fault code on my curtis hand held computer

[Carts4you]

Originally Posted by movin-on

Did you check the motor...A bad motor can take out the controller...

I have not. But could the motor be damaged from towing in run position?

[movin-on]

As Sergio has stated....Pulling the cart while in RUN will create a tremendous amount of heat in both the Motor and the Controller Armature driver.

[Fairtax4me]

Yes, towing the cart in run position will fry the brushes and can overheat and even melt the armature.
If it was towed in Run, Motor has to be taken apart, inspected, and repaired or replaced. No two ways about it.
Do not install a new controller until you know the motor is fixed. A short in the motor will damage the new controller.

[Carts4you]

Originally Posted by Fairtax4me

Yes, towing the cart in run position will fry the brushes and can overheat and even melt the armature.
If it was towed in Run, Motor has to be taken apart, inspected, and repaired or replaced. No two ways about it.
Do not install a new controller until you know the motor is fixed. A short in the motor will damage the new controller.

Thanks. Running tests on the motor today. On this specific car we only had a HDW Failsafe code. The controller was warm and the resistor on the solenoid was very hot/burnt on one side.

Again, we also found that this resistor was hot even when the car was not operating or charging. Why would this happen?

[Fairtax4me]

The resistor is hot because there is a short to pack negative in either the controller or motor, or both. This is causing excessive current flow through the resistor causing it to heat up.

The main reason the resistor is there is to provide a circuit to allow low current to pass by the solenoid to charge the capacitors inside the controller. This only takes a few seconds the first time the controller is connected to power, and once the caps are charged they stop pulling current, so the resistor never has a chance to get hot.

Usually it is a failure in the controller that causes it to get hot, that failure exhibits itself as heat in the controller as well, since current moving through the resistor will have to also move through the controller.
Sometimes a short in the motor can cause the same problem. A short in the motor can also instantly damage a new controller, so it’s very important to make sure the motor does not have internal damage before installing a new controller.

[Sergio]

The purpose of the pre-charge resistor is to keep the capacitors inside the Controller charged between Solenoid closures.

Under normal resting condition there is less than 10mA (0.01 Amps) going through the resistor and de to its power rating the heat developed is easily dissipated.

When the cart is in RUN mode and the controller detects involuntary motion, it powers the Motor Field coils and shorts the Armature coils, that prevents the motor from easily moving, but the heat generated by the induced Armature current is dissipated inside the Controller.

If the cart is towed in this mode, there is a possibility for both the Motor and Controller to overheat and be damaged, specially the enamel on the Motor coil wires or devices inside the Controller.

Remove all wires from the Motor and check if the pre-charge resistor is still getting hot, if it is, the problem is with the Controller.

If the pre-charge resistor does not get hot when the motor is disconnected, the issue is with the Motor.

[Carts4you]

Originally Posted by Fairtax4me

The resistor is hot because there is a short to pack negative in either the controller or motor, or both. This is causing excessive current flow through the resistor causing it to heat up.

The main reason the resistor is there is to provide a circuit to allow low current to pass by the solenoid to charge the capacitors inside the controller. This only takes a few seconds the first time the controller is connected to power, and once the caps are charged they stop pulling current, so the resistor never has a chance to get hot.

Usually it is a failure in the controller that causes it to get hot, that failure exhibits itself as heat in the controller as well, since current moving through the resistor will have to also move through the controller.
Sometimes a short in the motor can cause the same problem. A short in the motor can also instantly damage a new controller, so it’s very important to make sure the motor does not have internal damage before installing a new controller.

Thank you for the info. Looking at the motor today for shorts.

[Carts4you]

Originally Posted by Sergio

The purpose of the pre-charge resistor is to keep the capacitors inside the Controller charged between Solenoid closures.

Under normal resting condition there is less than 10mA (0.01 Amps) going through the resistor and de to its power rating the heat developed is easily dissipated.

When the cart is in RUN mode and the controller detects involuntary motion, it powers the Motor Field coils and shorts the Armature coils, that prevents the motor from easily moving, but the heat generated by the induced Armature current is dissipated inside the Controller.

If the cart is towed in this mode, there is a possibility for both the Motor and Controller to overheat and be damaged, specially the enamel on the Motor coil wires or devices inside the Controller.

Remove all wires from the Motor and check if the pre-charge resistor is still getting hot, if it is, the problem is with the Controller.

If the pre-charge resistor does not get hot when the motor is disconnected, the issue is with the Motor.

Sergio thank you for the detailed information. I am checking the motor today.

[Carts4you]

So we have tested the motor. We are not getting continuity between A1-A2 nor F1-F2. However when checking continuity between posts and casing we get continuity even without turning the wheels. Would this indicate replacement or is there a chance for repair?

[Fairtax4me]

I'd probably call that one toast. You can remove it and open it up to inspect it, but it probably has damaged field windings, and there's a high chance the armature is damaged beyond repair.