Dead batteries reading fully charged?

[o4mustang70]

I don't know anything about these carts but trying to quickly learn. I have a 1988 36v Marathon All you here when you press pedal is click. The batteries read 38.4 volts when tested in a series and exactly 6.4volts separately. All of them read the same thing. Is it even possible I need new batteries? I don't see how with the voltage reading but like I said I know nothing on these. I did replace the speed controller so rule that out. Thanks a lot for any advice.

[simple man]

See what voltage you read when you try to move the cart. Does it drop considerably or stay about the same?

[o4mustang70]

No change in volts at all. 38.4

[skuhleman1524]

Did you check the f/r switch?

[Sir Nuke]

Mustang....seeing as how your solenoid CLICKS, that is a good sign, as your activation circuit is complete. where your problem is, is in the high current (LARGE CABLES) part of your drive system. you have a lose connection somewhere.

[JohnnieB]

Lift rear tires off ground and put on jack-stands so half-ton cart doesn't take off unexpectedly and run over someone or something.

Connect your DVM between the B- and M- terminals on controller.
Push pedal until solenoid clicks.
You should read FULL battery pack voltage .
If not, you have an open or very high resistance in the high current circuit.

Attached in a schematic with the high current circuit highlighted.

[o4mustang70]

Thanks for the advice to all. I will be working on the cart this afternoon and will post the results. My eleven year old daughter thanks you as it is her cart.

[radioman]

04mustang70; Isn't this same cart you asked for help on May 19 (88 marathon No Go Batteries) and I made the following reply suggestion?

"You might have a bad solenoid. Measure the voltage on both big terminals of the solenoid (the contacts) when it energizes. (You will measure voltage on both lugs when it is not energized because of a pre charge resistor that is supposed to be across the contacts.) You should measure full battery bank voltage across both. 37-38 volts would be a good reading when energized. However this would not have caused the earlier problem not to go in reverse. That might be another problem. If you get good voltage on both solenoid terminals solenoid is not likely the problem and will have to dig deeper.

Since the charger is not cutting off like it is supposed to you might have a battery charger problem too. Check the water level in batteries. Please furnish charger model # and any additional information on cart exact model. Look through the stickes and see if you recognize your cart's operating system.

Sorry this is not much help but this will get you started troubleshooting. Maybe some more help will show up. You might browse through some other post and the stickies might help you understand a little of how these things work and the problems and headaches they can cause."

[o4mustang70]

Had a chance to do some more tests. The full pack reading is 38.8. Each individual battery is at 6.4. The cart is a 1988 Marathon Serial number 503116 Manfg. # k2788.

Jonnie B. The voltage between B- and M- is around 30v. When you pressed the pedal is goes down to 0 or close to it (.3?)

Radioman: Voltage across the two terminals on the solenoid is 5.3 when charged. When you press the pedal it goes to 0.
The Charger is a Total Charge III Model# 26984. The water level in all the batteries are over the plates.

I appreciate both your help and response to this problem. I wasted 250 on a controller yesterday and do not want to waste any more money as I quickly am finding out parts are costly for these toys.

I am going to check all connections as I wait for a response Thanks again

[o4mustang70]

Upon looking at some of the large cable connections the 2nd post from the rear of cart on the motor was dark and burnt looking. When I put a wrench on it, it snapped off easily. It was corroded and brittle. I assume the motor is burnt and needs to be rebuilt. Is rebuilding the best option?