Charger Circuit breaker keeps popping
 

I have a 2002 Club Car DS with Ranger Batteries. I plugged it in last night and it was not charged this morning.

I brought it back in and plugged it in again and the charger came one, shut off and came on again like it is supposed to do. I went out to the garage about 15 minutes later and the charger was off. I played around with it a bit and it came back on. It was charging for six hours and was still pulling 11 amps. I checked the cells with a hydrometer and they are not even close to charged. I borrowed a charger from a friend and plugged it in. It also booted up and was charging just fine. When I went o check on it an hour later it was off, but the batteries were not charged. I noticed that the circuit breaker had tripped.

What could be causing this?

It could be the OBC "on board computer" sending the wrong signal to control the charger. If you can check the output voltage the the pack of batteries is receiving from the charger.
What is the age of the Ranger Batteries?
Do you have any voltage from the main + terminal to the cart chassis, check with digital meter.

I'm guessing it's the OBC as well. I don't have a voltage meter. The Rangers are between two years and two months. Several of them had to be replaced two months ago.