Clubcar periodically goes into 8mph slow mode speed sensor already replaced

[scottyb]

Also you need to go back to using a voltage reducer for your 12v accessories. Not using one WILL compromise the battery pack

[mjroman20]

This sounds like a "main welded" fault issue. Provided the contactor is not actually welded; if it is a stock 1510 clubcar apparently had some issue where the controller was not reading the cap voltage vs the tow/run input voltage which resulted in a main welded fault. The effects of that fault don't become apparent until after you cycle the pedal.

More specifically
Run Mode > Key > Dir > throttle. the cart works fine.
Release throttle> solenoid opens > re-throttle. then the cart faults.
Cycle Town/Run > Key > Dir > throttle. cart works again.

Clubcar's quick-fix field solution seemed to be to put a diode in line with the tow/run into the controller. The voltage drop over this "widened" the acceptable voltage variance range preventing the fault. They actually have a harness adapter and official part number, though I don't have it on me.

[TahoeDawgZ71]

Originally Posted by mjroman20

This sounds like a "main welded" fault issue. Provided the contactor is not actually welded; if it is a stock 1510 clubcar apparently had some issue where the controller was not reading the cap voltage vs the tow/run input voltage which resulted in a main welded fault. The effects of that fault don't become apparent until after you cycle the pedal.

More specifically
Run Mode > Key > Dir > throttle. the cart works fine.
Release throttle> solenoid opens > re-throttle. then the cart faults.
Cycle Town/Run > Key > Dir > throttle. cart works again.

Clubcar's quick-fix field solution seemed to be to put a diode in line with the tow/run into the controller. The voltage drop over this "widened" the acceptable voltage variance range preventing the fault. They actually have a harness adapter and official part number, though I don't have it on me.

Totally agree

The diode that you're speaking of is only for the early DS IQ car. The later DS IQ and all Precedent models are supposed to have the diode in the wire harness already. But that doesn't mean that the diode hasn't failed.

[Sergio]

Hold on, the harness is called "main drop out", not "main welded" right?

I never heard of anyone having that issue after the cart totally stopped and the solenoid opened.

That issue was when the controller was switching from "Regen" to "Motoring" and since the solenoid never opens in this case, the firmware incorrectly sensed a voltage differential it did not like and opened/dropped the solenoid, not put the cart in limp mode.

[TahoeDawgZ71]

Originally Posted by Sergio

Hold on, the harness is called "main drop out", not "main welded" right?

I never heard of anyone having that issue after the cart totally stopped and the solenoid opened.

That issue was when the controller was switching from "Regen" to "Motoring" and since the solenoid never opens in this case, the firmware incorrectly sensed a voltage differential it did not like and opened/dropped the solenoid, not put the cart in limp mode.

You're right. I spoke too soon. Too early for me to be up I guess.

[mrgolf]

In all my reading on this web site I have only read about two things that cause a cart to go into limp mode, or slow to 8 mph. One is speed sensor and the other is the solenoid sticking causing the controller to put cart in limp mode. From that I guess you could have a bad controller that could do the same thing.

[mjroman20]

Originally Posted by Sergio

Hold on, the harness is called "main drop out", not "main welded" right?

I never heard of anyone having that issue after the cart totally stopped and the solenoid opened.

That issue was when the controller was switching from "Regen" to "Motoring" and since the solenoid never opens in this case, the firmware incorrectly sensed a voltage differential it did not like and opened/dropped the solenoid, not put the cart in limp mode.

Ah hell, right, it was main something. The specifics of that situation:

Voltage compared from B+ aux, pin 9 to the B+ bus bar. At armature current under 40A, and if the voltage drop exceeded 312 mV a main dropout is triggered

an external diode in the B+ Aux line. doubles the voltage differance

Still sounds like you are getting a main welded though based on the description of the issue. My previous suggestion just wont fix it...

[Sergio]

We all agree the issue is likely the Solenoid contacts are sticking/welded, I am glad David questioned if the OP had listed every part he ever changed or just the ones changed in an attempt to fix the problem.

[mjroman20]

One other fun fact; a main welded fault can be triggered by an issue with the pre-charge in a similar fashion to the main dropout. Internally the B+Aux pin from the tow/run feeds the cap bank through a pair of parallel bi-metal thermal switches and a diode. Again voltage on the cap bank being compared to the B+aux in every time the solenoid opens or is about to close.

That said if OP has eliminated the possibility of the solenoid sticking or welding, then either the external or internal precharge may be the next step.