Electric motor diagnostics

[RT-1]

My 80+ year old neighbor just purchased a used 2001 TXT PDS EzGo cart. He wants it to drive around the neighborhood with his dogs. Life's little joys.

The previous owner of the cart told him it was fine - just needed batteries. We set the charger up all night on the old batteries (after topping off fluids and cleaning cables) and never got a reference voltage above 36. 6 New batteries later, we have 38.2 volts.

The cart was very jerky when it would move at all on the old batteries. New batteries have not helped. I adjusted the ITS - it was significantly off - with no help at all. I found the service manual and I am walking though the diagnostics. The beep codes tell us it has the Freedom program. After holding the accelerator pedal all the way down (with zero response from the motor) I get a 4-1 beep code. Armature open.

I have gone down the diagnostic tree to the point where it asks for voltage between battery B- and controller A1. I get 12 volts here. It is supposed to be reference voltage. Checking at motor A1 gives me 13 volts. Again, it is supposed to be reference voltage. Then, we check voltage between B- and motor A2. This time, I get 38.1 volts. The diagnostic tree says, "replace motor."

My question is this. Best I can tell from the pictures, A1 and A2 go through the brushes. Is this correct? Wouldn't a better approach be to replace the brushes before a full motor replacement? Am I missing something? If it does need a motor replacement - are there sources of good used motors? This is going to be a once a week around the block cart.

[Sir Nuke]

the real PDS cart guru's will give you the best motor answer....but seeing as how your neighbor just bought a set of new batteries.....you/he need to remember proper battery break-in and charging etiquette. ALWAYS keep the batteries charged.....always.

Here is some very important battery info.

http://www.cartsunlimited.net/Batter...n_Methods.html

http://www.cartsunlimited.net/Batter..._Tutorial.html

[RT-1]

I appreciate that. Unless we get this thing running, going below 75% isn't going to be much of an issue...

Here's hoping the PDS gurus have the magic answer.

[RT-1]

OK - so, I have a personality disorder where I have to keep digging until I find something. I pulled the motor, split the case and found this:
IMG_1558.jpg
IMG_1559.jpg

The A1 and A2 posts are indeed straight to the brushes. The broken wire would certainly explain the voltage reading I had. I'm ordering new brushes right now and will post back. I hope this saves someone else $500+ from following the service manual's recommendation to "replace motor."

[chloe]

Good post. And you are correct, many would just replace the motor.

[RT-1]

I promised an update, so here it is. I ordered the brushes from BlockbusterGolfCars.com at almost 5PM Tuesday. They had them in the mail Wednesday morning and I got them Friday. I installed the brushes today - complete success. The cart is like new. Amazing acceleration - way to fast for its own good. I'm sure glad I didn't just order a new motor. Thanks for everyone's help.

[chloe]

Hope your neighbor enjoys his new ride.

[mgray70]

You never know! If you have nothing to lose you might as well bust in to it and see if you can fix it. Good job!