Navitas-converted Club Car Precedent Stops/Lurches

[ACHiPo]

Last spring I converted my 2006 Precedent to lithium and a Navitas AC drive.
Overall the conversion has been fantastic.

The last couple of weeks, however, my cart has been locking up then lunging. It is most common at slow speeds. Often when I let off the pedal a bit. Tonight it completely stopped on the way home. Toggling the tow/run switch got it going again.

I suspect either the tow/run circuit or the Navitas regenerative braking. Adjusting the controls does not seem to have any effect.

I checked the iPhone Navitas app and it does not show anything useful to diagnosing the problem.

What suggestions do you have?

Thanks,
Evan

[fstop]

Originally Posted by ACHiPo

Last spring I converted my 2006 Precedent to lithium and a Navitas AC drive.
Overall the conversion has been fantastic.

The last couple of weeks, however, my cart has been locking up then lunging. It is most common at slow speeds. Often when I let off the pedal a bit. Tonight it completely stopped on the way home. Toggling the tow/run switch got it going again.

I suspect either the tow/run circuit or the Navitas regenerative braking. Adjusting the controls does not seem to have any effect.

I checked the iPhone Navitas app and it does not show anything useful to diagnosing the problem.

What suggestions do you have?

Thanks,
Evan

When this happens, do you hear the buzzer (the one you hear for a second or so when you flip the run/tow from tow to run)? If you do, you may be right in suspecting the run/tow switch or power wire to the controller. It could also be a intermittent power switch or connection issue with your lithium battery's "power" button / circuit. Not sure what battery you have - some have a way to switch off power to the terminals, some don't.

Good luck pinning it down.

[ACHiPo]

Originally Posted by fstop

When this happens, do you hear the buzzer (the one you hear for a second or so when you flip the run/tow from tow to run)? If you do, you may be right in suspecting the run/tow switch or power wire to the controller. It could also be a intermittent power switch or connection issue with your lithium battery's "power" button / circuit. Not sure what battery you have - some have a way to switch off power to the terminals, some don't.

Good luck pinning it down.

Thanks. I was hearing a noise last night--not the reverse buzzer, but a periodic staccato buzzing much quieter than the reverse buzzer. It seemed to be coming from the Navitas controller. Flipping the tow/run switch silenced the noise.

I am using the Extreme Team Evolution 48V/100ah battery.

[fstop]

Originally Posted by ACHiPo

Thanks. I was hearing a noise last night--not the reverse buzzer, but a periodic staccato buzzing much quieter than the reverse buzzer. It seemed to be coming from the Navitas controller. Flipping the tow/run switch silenced the noise.

I am using the Extreme Team Evolution 48V/100ah battery.

The Navitas controller actually uses the reverse buzzer to also signal error conditions with a ticking / clicking sound. It's hard to hear on mine because I have some foam wrapped around the speaker so the reverse sound isn't so loud. I thought the sound came from the controller - the Navitas guys said the sound comes out of the buzzer (but isn't the buzz). Not sure how they manage that, but you might make sure the main page in the app doesn't show a yellow exclamation / error code at the top when you hear that sound.

[ACHiPo]

Originally Posted by fstop

The Navitas controller actually uses the reverse buzzer to also signal error conditions with a ticking / clicking sound. It's hard to hear on mine because I have some foam wrapped around the speaker so the reverse sound isn't so loud. I thought the sound came from the controller - the Navitas guys said the sound comes out of the buzzer (but isn't the buzz). Not sure how they manage that, but you might make sure the main page in the app doesn't show a yellow exclamation / error code at the top when you hear that sound.

That's a good lead. That's exactly what it sounded like--chirps coming from under the cart (much quieter than the buzzer but the same tone). I did not see an error in the app, but was scrambling to continue playing golf and get home so I wasn't very thorough--basically just tried things to get it to stop, which flipping the run/stop switch did.

I'll call the dealer and maybe Navitas tomorrow. Maybe there is a way they can interpret diagnostics.

[ACHiPo]

Talked to Navitas. They determined the problem was the controller to motor harness. A replacement will be sent Tuesday.

[fstop]

Originally Posted by ACHiPo

Talked to Navitas. They determined the problem was the controller to motor harness. A replacement will be sent Tuesday.

Sounds likely. I had a different issue a while back and while troubleshooting it I noticed the molex type connection at the cotroller for the harness you are talking about seemed like there was excessive play and resulting potential intermittent connection. I fabricated something to keep it pulled in tight w/o possibility for movement and have never had the issue since.

IIRC, the pins in the molex were set back a ways inside the plastic - take a look at yours when you pull it out and compare to the new one they send you. I'd be curious to see if there is a difference in that regard.

[ACHiPo]

I did get the current error Friday when I was diagnosing it. I also got 4 chirps followed by 5 chirps. The Navitas tech seemed quite sure he had the problem nailed. I have not torn into it yet to see if there's an obvious issue with the harness.

[PingEye3]

Originally Posted by ACHiPo

Last spring I converted my 2006 Precedent to lithium and a Navitas AC drive.
Overall the conversion has been fantastic.

The last couple of weeks, however, my cart has been locking up then lunging. It is most common at slow speeds. Often when I let off the pedal a bit. Tonight it completely stopped on the way home. Toggling the tow/run switch got it going again.

I suspect either the tow/run circuit or the Navitas regenerative braking. Adjusting the controls does not seem to have any effect.

I checked the iPhone Navitas app and it does not show anything useful to diagnosing the problem.

What suggestions do you have?

Thanks,
Evan

This sounds like a similar issue on a stock controller when the MCOR is going bad. Try this, KS off, pump accel pedal fast 10-12 times, then power up and try it. If is is smooth then, time to replace the MCOR2. How the Navitas acts when the MCOR is failing my be a little different than with stock controller.

[ACHiPo]

Originally Posted by PingEye3

This sounds like a similar issue on a stock controller when the MCOR is going bad. Try this, KS off, pump accel pedal fast 10-12 times, then power up and try it. If is is smooth then, time to replace the MCOR2. How the Navitas acts when the MCOR is failing my be a little different than with stock controller.

I thought it was the MCOR initially. I monitored the app while driving and the accelerator showed depressed even though the cart was lurching and acting like it wasn't.