Confirming Fried Controler - 48V TXT - fixing someone else's mistakes

harvesterguy

I've been tasked with fixing a 2011 48V TXT that has been worked on by a mechanic with no manual or knowledge of electric carts. I suspect a faulty controller but too many things have been monkeyed with for me to have confidence in my diagnosis. I'm not finding the TXT manuals to be nearly as helpful as the Medalist manuals I'm used too. Any input and advice would be greatly appreciated!

Here is the sequence of events:
1. Cart functioning fine with <2 year old batteries
2. Cart sits for extended time in Run Mode
3. Batteries low - Charger doesn't not bring batteries up (Pack voltage too low for charger to kick in or faulty charger?)
4. Mechanic replaces batteries without switching toggle into tow/maint
5. Cart still no go. Mechanic replaces solenoid with cart in RUN
6. Cart still no go. Mechanic monkeys with ITS from bottom side with cart in RUN
7. Enter me
8. Pack Voltage = 45.2 Charger will not engage, blinks slow, single red flash. Does the charger require a working controller to kick in? No evident wiring issues aside from charging wire being connected straight to battery instead of solenoid.
9. Solenoid will not engage. No ground on blue wire from controller.
10. Solenoid engages when grounded but still no go
11. Voltage at key switch and f/r rocker = ref volts
12. ITS micro switch has ref volts and continuity when pressed
13. ITS coil 0 volts on either terminal regardless of pedal position.

Is the controller dead or does the low pack voltage prevent operation? Is the charger issue the result of the controller or is the charger bad?

Any input will be greatly appreciated!

-Harvesterguy

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

bronsonj

Hi Harvesterguy,

You do not need a functional controller for the charger to work.

I would have thought that at 45+ volts the charger would work. Could be a fried charger.

I don't know what the cutoff voltage is on a stock controller. If it's 46.04v that is 10% capacity and the pack is generally considered dead at 50% (48.4v).

Try to find a different charger to test with or see if there is an issue inside the charge port on the cart before replacing controllers.

If you can post a picture of the odd wiring you saw that may help too.

orangeman6

Definitely not an expert here, but the comment about the charging wire being connected to the solenoid doesn’t sound right to me. When I had a lead pack, the wires from the charging port went straight to pack +, - . How would it charge through the solenoid? That might be why the charger won’t kick on??

Again, maybe I missed something, or have no idea what I’m talking about. Haha, but I’ve never read that before.

JohnnieB

FWIW: Pre-1996 Medalists and others had the wires from the charger port wired to the battery side large terminal on the solenoid (B+) and the B- terminal on the controller. See attached schematic of 94/95 Medalist.

Attached Images

949536v.jpg (59.2 KB, 0 views)

jkredman

Is the charger OEM, or after market?

Newer chargers monitor battery temperature by measuring the temp on the positive terminal of the pack.

Just guessing here, but if you have a late model charger / connector, it may be thinking there is a temperature issue.

Don’t know for sure, but if things were modified before you got ahold of the cart; could some change like this have been made?

nickdalzell1

By blinking LED flashing one red it sounds like the PowerWise QE. Those fail often but my guess is that the batteries are too low for it to attempt charging. 45V is way too low. they stop trying to charge if it gets below 46V. A good rule is for automatic chargers without a timer knob, 3 volts below the rating of the car is too low for it to detect a pack and charge. We got tons that come in as 'dead battery specials' during winter because of this, and there's just no reasoning with irate customers because they insist their charger is faulty because (in their words) "a charger's job is to charge dead batteries!"

We get tons of 'mechanics' also that think they know a golf car and again, there's no reasoning with them. They think they're saving some $$$ and cost themselves far more by attempting to work on their own car, and you also can't say anything as again, "I was a mechanic before your father was in diapers!"

Tons come in with failed controllers and when i ask about the run/tow switch i know it's the controller the instant i hear 'the wha?'

FYI: the TXT48 car will auto-shut down if the pack volts drop below 46V. Backup alarm and other stuff will stop working until it gets at least 47V SoC.