Ez Go Textron Charger (older) Troubleshooting Help

[mikdeb33]

Hi there all,

First if I have duplicated this thread I apologize. I have seen and read a lot of great threads here regarding troubleshooting and repair of the 36V chargers, the problem is they seem to be for the newer model chargers. I do not know how much similarity there is from the older chargers to the newer ones, I do know, with the cost of a new one, I am going to try to fix this one....

So here is my issue: I have owned my Golf cart since last spring. Had to replace a couple of the batteries but overall health and running of the cart is good. However, I have always questioned why when I charge the cart the charger never goes above 5 amps on the gauge (even with a near dead cart) Personally, I assumed the gauge was broke. So we are finally using it again now camping and I have a chance for real world tests and these are some of my results. From my readings in the various threads I think I do have a couple of problems but would like a more qualified individual to chime in their thoughts.

Charger plugged into 120V not to cart: Charger hums and puts out just over 36 volts. (One thread I read I thought said no volt or hum if not plugged in) Is this true?
Charger plugged into 120V and cart charging: Appears to be max of 37V across terminals when charging cart and gauge showing less than 5 amps.

Timer works good as it's supposed to.

So from what I have read it seems like I do have a problem with probably a capacitor.... But do I have another problem because of voltage when not charging?

I am assuming this charger was made in 1982 (Based on the 82 prefix to SN) but cannot find a model number. So any help going down the troubleshooting rabbit hole would be greatly appreciated.

Mike

[JohnnieB]

What you've got is an early ferroresonant transformer type charger.
Contrary to what is written on the faceplate, that is not an automatic charger. It is turned on and turned off by a timer.
(It was labeled that way because it predates what we now call automatic chargers, and to a degree, there is some automation built into it)

Later versions of the ferroresonant transformer type chargers, had control boards that turned the on when they were attached to the cart and the battery pack voltage was above a predetermined voltage and shut them off when the on charge voltage reach the 44-46 volt range (for a 36V charger), or after 16 hours if that voltage wasn't reached.

Except for the earlier versions being turned on and off by a timer and the later versions being turned on and off by a control board, they are basically the same charger.

The transformer and capacitor are matched pairs, so the capacitor values do vary between versions and you have to replace the capacitor with the same value as the one originally installed.

If it is not putting out above 5A when it is first plugged into the cart, the capacitor might be bad, or you may have one of the two diodes blown, or the transformer is bad. Except for the timer and ammeter, that is about all there is in the box.

If you are only measuring about 36VDC when not plugged into cart, the charger is not fully charging your batteries. Open circuit voltage ought to be well above 46VDC.

Open the case and connect an AC voltmeter between the wires going from the transformer to the two diodes.
With the capacitor connected, you should get 90VAC +/- 7VAC.
Without the capacitor, you should get 60VAC +/- 5VAC.

[cbv123]

I have that exact same charger. Except my ammeter is completely shot, needle never moves.

When I first got the cart, it would charge the batteries but it took FOREVER! As in, 2 or 3 full cycles through the 12 hour timer. I also strongly suspected the capacitor.

While pulling the capacitor out to check the values, I noticed a loose connection on the back of the ammeter. Tightened it up and now the thing charges like a champ! Rarely turn the timer to more than 6 hours anymore.

The timer controlled chargers would be, what, 30 years or more old by now? Plenty of time for connections to get a bit loose. Definitely worth opening it up and having a look-see....

[mikdeb33]

JohnnieB and cbv

Thanks for the advise guys. Yup, have not taken this apart yet to see what I got. Now that I have some idea what to be looking for and the fact I may have a problem I am going to open it up tonight and have a look see. I will let you know how it goes.
Thanks

[cbv123]

Originally Posted by mikdeb33

Yup, have not taken this apart yet to see what I got.

As JohnnieB said, this is a VERY simple charger. I think you're going to be amazed at just how few parts there are in there, so it's not going to be too tough narrowing down the problem.

The other good news is that aside from the transformer, every other item in the circuit can be replaced fairly inexpensively.

If the transformer's shot, just buy a modern charger.....

[mikdeb33]

Woo hoo, well the good news is I got it fixed. The cause was only one of the 30 amp fuses blown. And I can't even say it was blown other than no continuity through it. The thing was so dried out it just crumbled. Two new fuses and now I have the full charge working as it is supposed to. Thanks folks for all your help!!!