Forward is not that fast

[tylerolso]

I just bought my first golf cart and when i test drove it the guys said the battery were just low and thats why is was going slow. Well after charging it its still goes slow. In reverse it hauls butt, but when i try to go forward its slow. I put a volt meter on everything and each battery showed 6.31 to 6.36 and all together they should 38.1. I am new to these so any help would be great.

Also the cart is a Ez-go Marathon year 1992

[radioman]

Some preliminary things to get started diagnosing problem would be to measure the battery bank voltage while going forward and reverse. Check for hot connection around the forward reverse switch. How slow is slow?

[JohnnieB]

Your cart has a half speed reverse, so the high current cables to the motor's stator winding or the armature might be connected backwards.

Does the beeper sound when cart moves backwards?

Here is a schematic for the cart.

Also, the battery pack voltage is a little low, or it might be a lot low. Here is a chart.

The voltages given on the chart are taken about 12 hours after the charger shuts off automatically. If the are taken much sooner, they will be artificially high due to the surface charge they acquire while charging.

What charger do you have?

[tylerolso]

Originally Posted by radioman

Some preliminary things to get started diagnosing problem would be to measure the battery bank voltage while going forward and reverse. Check for hot connection around the forward reverse switch. How slow is slow?

When going forward and reverse with the pedal on the floor it reads 36.7 volts and it is slow enough i can walk faster then someone driving it beside me.

Your cart has a half speed reverse, so the high current cables to the motor's stator winding or the armature might be connected backwards. Everything was hooked up correctly accord to schematics

Does the beeper sound when cart moves backwards? beeper has been removed

Here is a schematic for the cart.

Also, the battery pack voltage is a little low, or it might be a lot low. Here is a chart.

The voltages given on the chart are taken about 12 hours after the charger shuts off automatically. If the are taken much sooner, they will be artificially high due to the surface charge they acquire while charging.

What charger do you have? A very old one that looks like it should be in a museum next to the first light bulb.

Today just to try it i switch the leads on the forward/reverse selector and forward was faster and reverse was slower but i just went around the block and it was almost dead. and it was on the charger all day yeasterday.

[radioman]

It appears you have either a set of bad batteries or a defective charger or both. You have the information here to help you determine what is wrong. Charger model would be useful info for those here offering to help you. Battery voltage reading when cart almost died would help diagnose your problem.

[JohnnieB]

If the cart moves, but doesn't move for very long, you have a battery pack issue.
Either there is one or more bad batteries; Or they are not being fully charged.

The cart not moving very fast can also be a battery pack issue, but can also be caused by excessive resistance the circuitry that connects the battery pack to the motor.

Resolving the battery pack issue will either fix the slow speed problem, or make it easier to troubleshoot.

From your description, I suspect you have one of the two charger types in the attached pictures. The case and faceplate may be different colors that the ones shown, but they work the same. The key difference between the two is whether the first number clockwise from the "OFF" position is a "1" or an "11". If it is a "1", it is a manual charger controlled by a timer and if it is an "11", it automatically shuts off when the battery pack's On-Charge voltage reaches about 45V and the timer knob points to how many hours it took to reach that voltage.

What are the pack voltage and individual battery voltages about 12 hours after the charger shuts off?

What are the pack voltage and individual battery voltages about half an hour after the cart stops, after being driven until is slows down?

[tylerolso]

Update

Right now i am charging each battery individually to see if the charger is the problem.

Also from the pictures i have the black manual charger.

Thank you for ya'lls help so far.

[tylerolso]

After talking to a local repair place they said to test the controller and i did and it failed, so i replaced it and now there is only a little bit of a different. I am gonna try and charger the battery's again and see what happens.

[JohnnieB]

Originally Posted by tylerolso

After talking to a local repair place they said to test the controller and i did and it failed, so i replaced it and now there is only a little bit of a different. I am gonna try and charger the battery's again and see what happens.

How, exactly, did you test the controller?

Attached is a simplified drawing of a series drive system, showing only the high current circuit. As should be obvious, the only difference between Forward and Reverse is which contacts are touching in the F/R switch.

As for charging the batteries, they should be fully charged at all times , other than when you are driving the cart.

[tylerolso]

Is it possible that my F/R is bad? Reverse is faster now and forward is only a little better.