1991 ezgo runs slow

[tgreen7]

This cart has not been run for 2 years. The batteries are fully charged and have been load tested good. The brakes cables are disconnected and wheels turn freely. When the throttle is fully on the cart moves very slowly in either direction. Once it gets moving it picks up speed and at times appears almost normal. With the wheels off the ground it appears to respond normally to the throttle. I suspect either the throttle control resistor assembly or the controller. How can I isolate this problem? What voltage should I be reading at the controller terminals with the throttle fully on? Thanks.

[mauistardog]

Welcome. At the top of the thread is a trouble shooting guide. or If you have the manual, it also has a trouble shooting guide that will take you step by step through each test. If I had to guess, then yea it is your controller. I would also pull the passenger side wheel and look to see if the hub is striped. I don't have my manual handy right now and it's been awhile since I ran that test. good luck
joe

[tgreen7]

I found the link to the trouble shooting guide but can't seem to access it. When I double click it it takes me back to the thread. Am I missing something? Do I have to wait some number of hours or days????

[tgreen7]

Posting a third time to see if that will allow me access to the trouble shooting guide.

[tgreen7]

The manuals and trouble shooting guides that I have found at the top of the thread are for 2001 and above. Can someone point me to a trouble shooting guide for a 1991 ezgo electric with a solid state controller?

[EZGO-MY-WALLET2]

have you put a meter on each battery and as a pack to check voltage before and 1-2 hour(s) after each charge ? What age are your batteries ? We will start with these questions and go from there and some of the more experienced folks here can chime in....

[mauistardog]

Try this

Testing of the EZGO ELECTRONIC SPEED CONTROL - SERIES & PDS
(NON DCS)
ALWAYS DISCONNECT THE NEGATIVE BATTERY CABLE BEFORE REMOVING CONTROLLER COVER. RE-CONNECT CABLE AFTER COVER IS REMOVED.
These test are to be conducted after making sure all wires and connections are clean and tight.
PLACE THE REAR OF THE CART SECURELY ON BLOCKS OR JACK STANDS FOR SAFETY
Connect (-) probe of meter on Battery Pack Negative (-) post. (This probe will on the post for the rest of the testing procedures) Connect (+) probe to the Battery Pack Positive (+) battery post. (This reading is the Battery Voltage and the amount of POWER TO THE CONTROLLER -
NOW, Key switch ON, gear selector in FORWARD, Place the (+) probe on the battery side of the solenoid's large post (If the reading is below battery voltage, check all wiring and terminals).
Place the (+) probe to the controller side of the solenoid's large post. The reading should be 0.1 to 3 volts less than battery voltage. If the reading is more than 3 volts less the battery voltage, the resistor is faulty. If the voltage is the same as the battery voltage, replace the solenoid.

Joe

[tgreen7]

Thanks Joe, I read this procedure in the trouble shooting guide but wasn't sure if it applied to the technology in my 1991 cart. I could not find a definition of the terms used in the guide. Does the term "series" refer to a vintage of cart or technology? I'm familiar with some of the terms like Marathon, Medalist, TXT and PDS but can't define the boundaries or describe the technologies included or excluded, e.g. solid state controller, speed control resistor, etc. Does such a definition table exist and can I get access to it? Based on your posting I will get back into the trouble shooting guide I was reading last night and try to isolate this problem. Thanks again.

[mauistardog]

You have an old Series motor golf cart. Its a EZGO Marathon with a Series motor. Your speed is controlled by a Controller..most likely a Curtis 275 amp controller. People will some times call it a Marathon controller cart cart to tell the difference between the old Marathon resistor carts. Different speed control system. Marathon is mostly refers to the body style( metal with two seatbacks). When trouble shooting it important to know the motor type (yours is a Series) and type of speed controller (yours is a Controller type), your throttle control...the little square aluminum box connected to the pedal linkage iis called a Potentiometer or POTS and is goes from 0 to 5K ohms. I am telling you this because if you have to buy one, club cars are 5k to 0 and don't work on your cart.
good luck on your testing
joe

[tgreen7]

I was able to get a diagnostic guide for isolating electrical problems on a Marathon with a controller from Greg Davis at the BGW Technical Support center. I measured the voltage between Controller + and Motor - terminals on the controller with the cart on jack stands and determined there was less then 2 volts at full throttle. The guide indicates under these conditions it should measure close to the cart reference voltage or full battery pack voltage, 37.7 volts in this case. Thanks to all who assisted in isolating this problem.