Alltrax DCX 400 Low Output diagnoses

[Jonny Two-Toes]

Any additional diagnosis tips would be helpful as I’m at a dead end.

2006-ish EZ-GO TXT PDS 36v. New batteries 38.3v at the pack. Alltrax DCX 400. 4 ga wire. Stock motor. 23” street tires.

Couple weeks ago cart started intermittently running slow. At times it would surge. With throttle fully depressed it surged from 100% to approximately 40% (with nothing between). I could stop and tap the solenoid and it would work fine again for a bit. This was a stock solenoid with no diode and no resistor.

Installed a “heavy duty” generic 36v solenoid with the 4 posts on top and a resistor and diode.

Cart is no longer surging, but is running slower. A month ago it went 23mph. Now it tops out about 12. I installed the diagnostic application, plugged in laptop and took it for a spin. On the linear throttle map, throttle position maxes at 56% and approximately 95 amps. On another throttle map, max throttle is 36%. These percentages are steady while the pedal is fully depressed.

Controller is not throwing codes. The Alltrax troubleshooting guide indicates that throttle position percentage is output, not input, in the sense that it is limited by max current output. I have all controller settings on max with no regen. I do not belive 95 amps is the max output for the DCX 400.

Any thoughts? I’m about to pull my hair out. I believe the controller is limiting the output for some reason right now. However the history over the last few weeks before changing the solenoid makes me question everything.

Best,

Jonny

[JohnnieB]

First of all, get some spray cleaner for electronic connections, then disconnect and spray clean all the plugs and jacks, then reconnect.

If that doesn't fix it, measure the voltage between Pins 1 & 2 on top of the DCX. Might have to lift the connector a bit to get to the pins.

Should be 10V when pedal is pushed just far enough to make solenoid click and smoothly decrease down to 6V as pedal is slowly pushed to floor.

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Motor might need brushes.

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ITS sensor may have gotten wet.

[Jonny Two-Toes]

I am thankful for this forum and the active users.

So, this morning I went to go diagnose with your suggestions and cart worked perfectly. Laptop tool showed 100% throttle and 420 amps at the initial load.

This is a head scratcher for me. I’ll update this thread if anything changes (which I am sure it will). I fear the controller may be self limiting output for some reason under some unknown condition (even though there is no fault code.

Best,

Jonny

[JohnnieB]