DCX300 dead after "tow" with switch in "run".

yourflorida

I think I killed my buggy.... Coasted to a stop and switched into Neutral while rolling.... cart slowed abruptly and NOW DEAD. Nothing..

Please describe the failure mode on these "regen" systems if moved only 5' with key ON and selector in NEUTRAL.

Such a simple action, anyone could shift into Neurtral while rolling, please tell me it is just a diode or something.

Thanks.

BGW

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JohnnieB

Since you say shifting to Neutral is a simple action, I suspect you have a PDS cart with a F/R rocker switch next to the Keyswitch.

Unlike the stock PDS drive system, when a DCX controller is installed using a DCX to PDS adapter, the yellow wire on the solenoid is fed B+ via the F/R switch, so when you shifted to Neutral, the solenoid de-energized and the regen voltage skyrocketed. Shifting to Neutral also shut down the DCX controller, so as it was powering down, it got hit with higher than normal voltage. You can get the same sequence of events by turning the key off while moving, or have the reed switch fail while moving.

If only moving at low speed as you indicated, I'm not sure if the over-voltage would have been high enough to damage the DCX controller.

I'm also not sure if Alltrax is aware this set of circumstance can be created in a PDS to DCX installation, so give them a call.

FWIW: The XCT in a PDS has a somewhat similar issue when the key is turned off while regen braking is engaged, but Alltrax solved that potential problem by installing a 6A diode across the solenoid contacts to keep the regen voltage connected to the battery pack when the solenoid de-energizes.

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As for the cart not working, we need to do some troubleshooting to determine if the DCX controller is bad, or something else has failed.

Does the solenoid click when the pedal is pushed?

yourflorida

BTW... Thanks for your very detailed reply all those years ago.

I ended up getting another controller. Still have the old one if I ever find a cheat sheet on "rebuilding" it.

It is people like you that make this site great. (and people like me that don't reply that suck. Sorry)

JohnnieB

Thanks for the followup, albeit belated.

Alltrax controllers are filled with a potting compound, so they are not repairable, or at least not easily so even if you could find a schematic.

Pop the rubber cover on the serial port and you'll see everything is covered with a shiny black epoxy like substance.