Controller issue

[ScottC01]

1999 club car DS 48volt powerdrive plus, dual solenoid. OK. I just picked this cart up for cheap money and put new batteries in it and a new upper solenoid and i got nothing still. i did notice that the resistor across the big terminals is very hot and still is hot even in tow and the key off. Obc is working and looks to be new because it charges fine. I checked the key switch and it is working as it should. solenoid does not click when the key is turned on or when you press the gas pedal down. Not sure where to go from here?

[Mooncarter]

Sounds like the first solenoid is stuck. Unhook the batteries until this is figured out.

[ScottC01]

There is power only going to one side of the big terminals. the side that comes from the +B but there is power to both of the small terminals with key off and on run...

[Mooncarter]

Pop off the cover and take some photos of your system with the 2 solenoids.

[ScottC01]

Wiring Diagram

[Fairtax4me]

Solenoid on the passenger side is the main power solenoid. On the driver side is the dynamic brake solenoid. Which resistor is getting hot?

If neither solenoid is clicking you'll need to check for power getting to the Small terminals at the solenoids. Should be close to pack voltage with Tow Run in Run. If no voltage at the solenoids, then need to check voltage at the OBC 6 pin connector, should have 48v going In on the white wire, and 48v coming Out of the OBC on the Blue wire.

[ScottC01]

The resistor on the main is getting hot, I have power to both small terminals with tow run switch on run.

[Fairtax4me]

Ok. You'll want to disconnect the pack negative, then disconnect the wires from the motor and test the motor terminals for continuity. You should have continuity from A1 to A2, and F1 to F2. There should be NO continuity from either A to either F. There should be NO continuity from any terminal to the case.
If there is continuity to the case the motor is damaged. Unfortunately that often will take out the controller with it.

If the Motor tests out OK it's likely the controller has failed, and is causing the draw that is making the resistor get hot. With the motor disconnected, tape off the ends of all of the motor wires so they do not touch anything or each other. Reconnect the battery pack negative and see if the resistor still gets hot. If it does, the controller is bad.

[ScottC01]

I don’t think I have got power past the solenoid yet. When I check volts on the big terminals I don’t have any on the second terminal but I have 49 volts at both small terminals but no click of the solenoid . I bench test the solenoid with 48 volts and it clicks and works but not in the cart even though I have power to both small terminals.... I am losing my mind.. lol

[Fairtax4me]

The controller provides the negative side for the solenoid. Controller gets all the right signals, commands negative for both solenoids then allows motion.
If the small resistor on the large posts of the solenoid is heating up is because there is a short circuit either in the motor, or in the controller due to a failure of one of the FET drivers that controls the current to the motor. There is higher current than normal moving through that resistor due to the short, so it gets hot.
The resistors only function is to provide a small amount of current for the capacitors in the controller to charge. Once they are charged there is no more current flow across the resistor, or it is minimal at most. The only reason it gets hot is due to a short in the controller or motor, or the solenoid not closing when it is commanded to close. You're not getting the command for the solenoid to close, combined with the hot resistor most of the time points to a failed controller.

Disconnect the motor, see if the resistor still gets hot. If it does, the controller has failed.