E-Z-GO Marathon Controller Golf Cart Very Slow

joe5427

New Member
I have an older E-Z- GO Marathon Controller golf cart (somewhere between 89-92) that was pertty neglected and wouldn't run when I first acquired it. I cleaned and checked all connections. Battery voltage is good at about 38 volts. I replaced the solenoid. I also jumped the power bypassing the F-N-R micro switch (MS-2) located in the front of the cart and is part of the main F-N-R switch as the microswitch seemed non-functional. By this I mean I have a jumper directly from the key switch to MS-3 located directly above the potentiometer in the center of the cart. The golf cart runs but is very slow. Also it seems to run slightly faster in reverse than it does in forward. By slow I mean approx 5 mph. Somehow controller comes to mind but I'm not sure at all.
 

HotRodCarts

Cartaholic
Welcome to the forum...

Try checking the batteries under a load (while driving the cart) and see how low the voltage drops...
 

joe5427

New Member
Bummer! When testing under load my 38 volts dropped right off the map hanging around .1 or .3 sometines getting as high as 3 volts. I also did this same test on my 97 Clubcar which has seemed a bit sluggish lately. It tested well staying at about 47.5 volts when under load. So I guess I should be thinking batteries in regard to the E-Z Go? Also do you have any ideas regarding my Club Car or should I write a new thread under the appropiate heading?
 

HotRodCarts

Cartaholic
If the voltage on the EZGO is dropping that low the golf cart would't move at all. I'd recheck the voltage under load but my guess is your batteries are shot and possibly some bad connections or cables.

On the Club Car if the voltage stays under 48 volts while driving on flat ground I'd say your batteries are getting weak. Make sure they don't need distilled water...
 

joe5427

New Member
You were correct! I had the batteries load tested and found one bad one. It's been replaced and the cart now seems to have acceptable power. One thing puzzels me though. This cart is definately faster in reverse than in forward. Any ideas? Smarter owner doesn't count. And by the way, thank you for all your help so far.
 

HotRodCarts

Cartaholic
No problem your welcome... The older EZGO's are usually faster in reverse if the half speed wiring isn't in tact.
 

joe5427

New Member
Okay, but I'm not sure exactly which wiring is the half speed wiring. So far as I know all the wires and connections have been cleaned and are in good and correct order according to the wiring diagram. Three small items are missing however. I believe they are a resistior and a diode both of these being part of the solenoid. Also there is a round nickel sized resistor (I think) that goes between B+ and B- on the control module. I've had difficulty locating these items and one dealer told me that they're not essential to normal operation. Also my understanding of exactly what these items do is pretty vague. Overload protection is what was told to me.
 

HotRodCarts

Cartaholic
The diode only lets current run one way. The resistor helps from having voltage spikes to the controller. The cart will run without them but it's best to have them in place...
 

joe5427

New Member
Thank you, that's the clearist information I've heard so far. I'm still in suspense about half speed wiring though (main function and how it works). Hope I'm not being a pain.
 

HotRodCarts

Cartaholic
No pain at all...

You should have 4 wires coming from the pot box. 2 of the wires go to a double micro switch located on the forward and reverse switch. That switch controls the half speed reverse. If the wires aren't connected the cart will run full speed in reverse. Most older EZGO's will run faster in reverse when the half speed wires aren't connected or the micro switch isn't working properly. How fast is the cart in forward. If you have a GPS check your forward speed. It should be right around 12 MPH...
 

joe5427

New Member
So, I guess the plan is to replace the double micro switch (MS-4 on my diagram). Also, I'm curious about MS-3 also located on the forward-reverse switch. Currently I've jumpered past this switch as it is also defective. It takes power directly from the key switch and feeds MS-3 which is mounted above the potentiometer. What does MS-2 do and could it be part of my current problem?
 
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