Total Charge 3 charger issues

[Robert Hutchins]

Hi I have an EZ Go total charge lll that is not working. It worked fine then just stopped when I touched thr charger plug to the cart it clicked, the amp meter would sweep to the right then back to 0. I tried it on another cart and it did the same thing so I ruled out the batteries. Found a diagnostic flow chart and determined that the control board was bad by jumping the relay wires, the trasformer hummed. I replaced ithe board now it does nothing. I ohmed the the wires, fuse and all checked ok so now I am wanting to check the diodes on the heat sink plate, the readings are 398 on one and 420 on the other is this good?

[JohnnieB]

There are two diodes, so there ought to be four Ohm readings.

With the Ohmmeter leads attach in one direction, each diode should read "Open" and should read a "Short" (or very low resistance) in the other.

If you are using the meter function that has a diode symbol, you should get "OL" in one direction and from about 0.450 to 0.600 in the other.

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All the control board does is turn the charger ON and OFF. Does the transformer still hum when you bypass the relay on the control board?

[Robert Hutchins]

Thanks for answering me!! Yes sir it does hum

[JohnnieB]

The nice thing about the TC-III and other ferroresonant transformer type chargers is that they are 100% repairable.

There are two main circuits: Battery charging circuit (Transformer, capacitor and diodes) and a semi-smart ON/OFF switch (control board), plus some ancillary stuff like ammeters, fuses, circuit breakers and MOVs.

Let's check/troubleshoot the battery charging circuit first.

The battery charging circuit does not need the control board to charge a battery pack, so bypass the relay and try to charge a battery pack with it.

Plug charger into cart first and then connect it to an AC outlet. The ammeter should climb into the 15A to 20A range and stay there for up to half an hour or so, unless the battery pack is near to full charge. Actually, the ammeter stays at the upper end of the scale until the On-Charge voltage climbs above about 40V and as the On-Charge voltage continues to rise, the amps start to decrease and will eventually drop into the 2A to 7A range and stay there forever as the On-Charge voltage continues to gradually rise. When the On-Charge voltage ceases to rise, the batteries are fully charged.

Let us know what if the charging circuit is working.

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Attached is the charge profile designed into the ferroresonant transformer and capacitor pair.

The PDF file is the TC-III/TC-IV manual.

[Robert Hutchins]

Thanks for the info, I will be out of town this weekend but I will let you know what I find when I return. Thanks again!!

[Robert Hutchins]

Sorry for the long delay in responding to the problem I was having, well when I replaced the circuit board I reversed the two wires that go to the relay. Switched them around and all is good!!. Thank you for your help with this