EZ-Go TXT Solenoid problem

[SSISeaPalms Sailor]

I had a dead solenoid on my 2013 TXT48. The coil was an open circuit. I replaced the solenoid, but still no click on pedal push. Is the pedal microswitch responsible for sending the 48v signal to the controller (Curtis 1206HB-5201) that tells the controller to output 48v to the solenoid coil? Or, does it take a combination of the microswitch and ITS for the controller to output 48v to the solenoid coil? I'm worried now that my controller is blown.

[JohnnieB]

B+ (battery pack voltage) is applied to one side of the solenoid coil by the keyswitch, which is fed by the Run/Tow switch. The controller applies B- to the other side of the solenoid coil when the pedal switch closes, if a direction is selected and the charger is not connected to cart.


With run/tow in run, key on, F/R in Forward and charger unplugged, you should have pack voltage on the following pins: 5, 8, 9 & 10. When pedal is pushed, B+ is applied to pin-6 and solenoid ought to click.

[SSISeaPalms Sailor]

Some additional diagnostics. The solenoid definitely works with direct connect to the battery pack. Voltage on pack is 50.9v.

I disconnected the yellow and blue wire from the solenoid and attached DMM. With ignition on and F-R in F position, I'm getting 46.7v without a pedal push. That doesn't seem right. Shouldn't it be zero volts until pedal push occurs? Voltage across the yellow and blue wires drops to about 45.7v with a pedal push.

I'll run additional diagnostics on the controller.

[JohnnieB]

Originally Posted by SSISeaPalms Sailor

Some additional diagnostics.

1. The solenoid definitely works with direct connect to the battery pack. Voltage on pack is 50.9v.

2. I disconnected the yellow and blue wire from the solenoid and attached DMM. With ignition on and F-R in F position, I'm getting 46.7v without a pedal push. That doesn't seem right. Shouldn't it be zero volts until pedal push occurs? Voltage across the yellow and blue wires drops to about 45.7v with a pedal push.

I'll run additional diagnostics on the controller.

All wires reconnected and negative test lead attached to battery pack's main negative terminal.

1. With Run/Tow in Run and Key on, you should get 50.9V on the small terminal with the yellow wire attached. If not, the key switch (or the Run/Tow switch) is bad.

2. These are probably phantom voltages. Your DMM likely has an input impedance of a mega-ohm or more and what you are reading is the voltage potential across two reverse biased P/N junctions due to the minuscule current leakage that all solid state components have.

[SSISeaPalms Sailor]

I suppose it is possible I have the yellow and blue wires switched on the solenoid, or would that matter.

[SSISeaPalms Sailor]

Following your instructions I'm reading pack voltage of 50.4v on yellow wire terminal, but I'm also reading 47.5v on blue wire terminal.

[JohnnieB]

I'm not sure. I've never laid eyes on a TXT-48 solenoid as installed, so I'm working off the schematic and it shows two wires (Yellow and Wht/Ylw) on one small terminal and one wire (Blu) on the other.

Of course a schematic is not a wiring diagram, so the two wires could be joined within the harness instead on being physically connected at the solenoid.

The coil itself isn't polarized.

[SSISeaPalms Sailor]

Well that's interesting. All that was connected to my old solenoid was one yellow wire. I suppose the wire from the key switch must be connected to the yellow wire at another point since it definitely puts pack power on the yellow terminal.

[JohnnieB]

Originally Posted by SSISeaPalms Sailor

Following your instructions I'm reading pack voltage of 50.4v on yellow wire terminal, but I'm also reading 47.5v on blue wire terminal.

Normally, you should get the same voltage on both sides of the coil when the pedal isn't pushed. The electronic switch inside the controller should be off and very little current should be flowing through the coil, so there shouldn't be any voltage drop across it. You are getting a ~3V drop, so the transistor (or whatever) that is used to connect B- to the solenoid coil when pedal is pushed may be bad. If so, the controller will have to be replaced.

The user programmable Alltrax XCT48400-TXT-48 is an excellent replacement for a Curtis 1206HB.

[SSISeaPalms Sailor]

Thanks for all your help. Is the Alltrax XCT48400-TXT-48 pretty much plug and play with the Curtis cables?