EZ go TXT no go....

[a65l]

Background... TXT, series, 36v.

Well, it goes for a little bit. I bought the cart, non-running, from a kid. Cleaned some stuff, mainly disconnecting connections and wire brushing and re-install, replaced ESC heat sink (only one bolt still able to thread in, and corrosion) and cleaned up the reverse switch. Replaced FLA's with Allied Lithium packs. Got it all back together, and what do you know.. it moves.

For a while.

The cart runs, moves, all seems good, then it will mysteriously die. I can hear the solenoid click. It takes 4-5 minutes of just sitting still and it will move again. The whole time I can hear the solenoid click. I've checked battery voltage while sitting, nice and solid at 40-41 volts.

I put the rear up on jackstands to do some troubleshooting. I checked voltage between the B- and M- connections on the ESC. The manual says that voltage should start at battery voltage and drop smoothly to zero. It does when the motor runs, and when the motor quits, that voltage becomes highly erratic and unstable.

I verified resistance readings between the motor terminals using the troubleshooting guidance in the forums. They were all in range, or very very close. I've laid my hand on the motor after it quits, and it's not warm.

I've verified that all the connections are clean and tight. Again, I hear the solenoid click every time. Based on the erratic voltage from above, I replaced the speed control. Still the same issue. I guess the diagnosis is fairly simple, but is there something I'm missing?

[kgsc]

You did replace the controller plate ?

[a65l]

The heat sink? Yes.

[bronsonj]

When it is moving, what is your voltage?
I assume you have the stock controller?
Can you tell us more about your cart? Is your cart series or sepex?
You said you cleaned up the reverse switch so I assume series.

[a65l]

Yes. Series cart, stock controller and motor.

I have noted the following: Cart runs for a very long time if I only go partial throttle. Do a full throttle run and it dies very quickly.

When I installed the replacement ESC I used the included heat transfer grease and not the pad.

Will dig the charge monitor out from under the seat and monitor battery voltages while I run it today.

[kgsc]

Originally Posted by kgsc

You did replace the controller plate ?

Originally Posted by a65l

The heat sink? Yes.

Okay just trying to clarify. If it runs for a while at partial throttle I would suspect heat being a problem. Just as a test move the wires on the fnr switch at the 3 o’clock position to the 6 o’clock position and from 9 o’clock to 12. This will bypass the fnr to see if that is your problem.

[a65l]

And as a bit of further info, I checked battery voltage during a period of no-going. AT that time, it was showing 39 volts. The battery voltage did not change when I pressed the accelerator and heard the solenoid click.

[a65l]

Nicer weather today so will try and bypass fnr switch and see if that solves issue. further updates as situation warrants....

[a65l]

So... drove cart to mailbox and back. Died in driveway. Feeling around on the fnr switch, I find the lowest terminal, on the back side, is noticeably hot to the touch. disassembly will commence shortly (actually, technically, at work today)

[mikec557]

Originally Posted by a65l

So... drove cart to mailbox and back. Died in driveway. Feeling around on the fnr switch, I find the lowest terminal, on the back side, is noticeably hot to the touch. disassembly will commence shortly (actually, technically, at work today)

As we all (almost?) sit here on house arrest, do please keep us updated on what you find. It's bound to help me/us sooner or later.

Thanks
Mike