Solenoid Clicks- Cart won't engage- 2005 EZGO TXT PDS

[EZGO1910]

2005 EZGO TXT PDS - My cart intermittently will not engage. It almost always works in Reverse, but won't engage in Forward. New, fully charged batteries. New Controller. I hear the solenoid click every time. I noticed when it's not engaging, the battery indicator light will fade from dark red to being very faint when I step on the pedal.Any help is much appreciated! Thanks!

[JohnnieB]

Unfortunately a "new" controller does not mean a "good" controller.

With a PDS, if the solenoid still clicks when the failure to move forward (or reverse) occurs, the problem is within the controller.

The solenoid clicking means the controller is being told to pass amps to the motor's armature and field windings. The difference between forward and reverse is the direction of current flow through the field windings. For forward F1 is + and F2 is -, for reverse F1 is - and F2 is +. The battery voltage going to the solenoid coil follows a slightly different path, but if the solenoid clicks with either direction selected, both voltage paths are good.

That leaves the controller being told to pass amps to the motor's armature and field, but it isn't doing it since cart is not moving.




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Replace the stock PDS controller with an Alltrax XCT48400-PDS (or larger) and your cart will do well over 20MPH with stock height tires and a 36V battery pack. XCT is user programmable, so speed can be turned down if so desired.

[EZGO1910]

Thanks for the fast response. The controller was replaced by a professional EZGO service company two months ago. I'm not positive which brand, but it's one that they use as standard for my cart. Ultimately, the service tech could not diagnose my issue of not engaging in Forward and was stumped.

Any other ideas apart from the controller?

[JohnnieB]

Originally Posted by EZGO1910

Thanks for the fast response. The controller was replaced by a professional EZGO service company two months ago. I'm not positive which brand, but it's one that they use as standard for my cart. Ultimately, the service tech could not diagnose my issue of not engaging in Forward and was stumped.

Any other ideas apart from the controller?

Was it a new controller (Curtis 1206MX - EZGO part# 73326-G07)?
Or was it a repaired/rebuilt/remanufactured controller?

Put the controller in diagnostic mode and listen for beeped error codes. The text at the bottom of the attached label tells you how to get into diagnostic mode and lists the error codes.

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The symptoms alone (if they have been stated correctly) eliminate everything except the controller. However there is a possibility that a bad field winding or bare F1/F2 cables (insulation wares through where they go around battery box frame - see attached picture) might be taking out the field winding portion of the controller.

[EZGO1910]

Johnnie, sorry I mislead you. They replaced the converter on my EZGO, not the controller. The guy I bought the cart from has some aftermarket controller on it that I'm guessing is causing this issue. I hope it's not the motor. I mainly use it in my neighborhood to get down to a lake and around the streets.

Question- What controller would you recommend for something reasonably priced and easy to install? I'd be happy if it goes 20mph, but not necessary. It is lifted with newer tires.

Thanks

[JohnnieB]

Until something better comes along, the only controller I'll ever recommend for a PDS or TXT48 is the Alltrax XCT.

If the cart has stock height tires (18" tall), standard differential gears (12.44:1) and no rear seat, the 300A version will suffice.

If the cart has tall tire (up to about 22") and/or a rear seat, the 400A version is needed.

For off road and tires over 22", the 500A version.

You mentioned your cart is lifted, so it most likely has tires over 20" tall and a minimum of the 400A version (XCT48400-PDS) is needed. Which is on sale for $462 at: https://www.cartsunlimited.net/alltrax-xct-sepex--.html

The speed is user adjustable by limiting the max motor RPM and the outputs are short circuit protected, so even if motor is bad, it won't take out the XCT controller.

[EZGO1910]

I just checked and my EZGO has an Alltrax DCX 400, I think within 5 years old. I'd hate to buy a new controller if that's not the issue.

Any other things to diagnose or try before buying a new controller that would be causing the intermittent problems of not engaging? Could the reed switch be an issue? Like I said, it always works in reverse, it's just when trying to engage going Forward it gives me problems. It will start to lunge forward and then stop immediately.

Thanks

[JohnnieB]

Originally Posted by EZGO1910

I just checked and my EZGO has an Alltrax DCX 400, I think within 5 years old. I'd hate to buy a new controller if that's not the issue. Any other things to diagnose or try before buying a new controller that would be causing the intermittent problems of not engaging? Like I said, when I push the pedal, the battery indicator light fades away when it's not working, but stays red when it engages fine.

Thanks

A DCX was a plug-n-play replacement for the DCS controller (Curtis 1206SX), which was a failed design and soon replaced by the PDS, which was a fly-by-wire system (Controller does everything, switches and other controls only tell the controller what you want to do). Instead of designing a new controller for the PDS, Alltrax designed and adapter cable that allowed a DCX controller to be used in a PDS cart, but sacrificing the RPM limiting features of the PDS.

Following the various voltage paths for a DCX installed in a PDS is akin to tracing a single strand a pasta in a large plate of spaghetti, but I used to run a DCX in my PDS, so I've done it. I also managed to explode my stock PDS motor, mostly due to the DCX not having a max RPM limit, which in turn took out the DCX controller.

I've reviewed my DCX in a PDS schematics and the symptoms still point to the controller, but the above statements highlighted in red may be telling us the DCX controller is in the bootload mode. (See bottom line of attached error code list.) If so, the DCX may be okay once it is put back into the normal operating mode.

Let's check the power up sequence.
No charger connected
Run/Tow in Run
F/R in either F or R.
When Keyswitch is turned on the LED on the DCX ought to flash green 4 times (indicating it is programmed for an ITS type throttle), then go to steady green.

What is the LED on your controller doing?

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Also, call Alltrax, they might have some suggestions.

[EZGO1910]

Thanks for the last response, that was helpful. It does blink 4 times upon startup, so that's fine.

When I engage the pedal to go forward, the LED blinks red 6 times. Your trouble shooting page says that means battery undervoltage shutdown. What is the undervoltage slider?

I have three new Trojan batteries this summer, and 3 Duracell from a year ago. All fully charged.

Thanks

[JohnnieB]

A DCX is user programmable and has a dozen or so parameters that can be adjusted and Under Voltage is one of them. (see attached)

The 6 red flashes means the battery pack voltage (As measured between the B- and B+ terminals on the controller) is dropping below whatever the Under Voltage is set for. However, it does it in one direction, but not the other, so something is cause a higher amp draw from the battery pack in one direction and not the other. (The LED dimming is also an indicator)

If the Field output from the controller is not forwarding and amps to the field windings in one direction, but not the other, the motor will be stalled in one direction and will draw max amps from the battery pack, dropping the battery pack voltage. So a bad controller is still the most likely suspect.

Also attached is a diode test for a DCX controller and a troubleshooting guide.

The diode test cannot prove the controller is good, but it can prove it is bad.

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Contact Alltrax and find out what they think about it.