91 marathon controller

carson398 · 05-24-2011, 08:11 AM

does anyone know a simple way to test a controller? I think mine has gone bad. It runs for a while then slows downto a crawl then stops. I just put a new solinoid on it. Could it be the pot assembly? Or does it sound like the controller. Could it be the motor?

scottyb · 05-24-2011, 08:31 AM

Disconnect 2 wires from the pot to the controller stick the 2 test leads in the 2 wire connectors on the pot wires. Set DVM to 20k ohms and watch the meter as you depress the peddle. The reading should rise to 5-6k ohms.

scottyb · 05-24-2011, 08:33 AM

With the cart on jack stands:
Do not rev the motor up hard while on jacks they can over spin and explode. Probably would be best to disconnect the motor leads from the controller first then test output.

Check the power output from the controller by connecting the negative probe to the controller's M- terminal and positive to the B+ terminal. Press the accelerator and watch to see if the voltage increases. It should increase from a reading of 0 to the full voltage of the battery. If the motor is not turning, the problem may be in the directional switch or motor. The controller is bad and must be replaced if there is no voltage.
I probably should mention controller test is done with at least one rear wheel jacked off the floor and key on, directional selector in forward. ~ test leads on B+ and M- should read 0v then push the gas and watch the voltage rise to full pack voltage?

shadowman · 05-24-2011, 08:33 AM

have you tested, load tested and checked the S/G on each battery? if not start there and check cables while your at it......................

carson398 · 05-24-2011, 02:27 PM

I have checked batteries they are all good. thanks for all the posts

tonywebb76 · 06-26-2012, 12:19 PM

I'm having a similar problem. Does no voltage from M- terminal and positive to the B+ terminal mean the controller is dead for sure, or can this be caused by something else. My Pot is not reading 5-6k ohms either. Does one cause the other?

91 Marathon.

scottyb · 06-26-2012, 04:25 PM

Quote:

Originally Posted by tonywebb76

I'm having a similar problem. Does no voltage from M- terminal and positive to the B+ terminal mean the controller is dead for sure, or can this be caused by something else. My Pot is not reading 5-6k ohms either. Does one cause the other?

91 Marathon.

You should check the basics first.
Does the solenoid click when you try to go? If no, you are probably not getting any power to the controller at B+. You can verify this with a voltmeter. You should have full pack voltage between B+ and B- when the solenoid clicks.... Let us know.

Marathon pot should measure 0-5k through it's travel.

tonywebb76 · 06-26-2012, 11:38 PM

The solenoid is clicking, and I'm getting 37.9v from B+ to B-. The pot is measuring 0-6k. I appreciate the help.

scottyb · 06-26-2012, 11:58 PM

So far so good. Put test leads on B- and M- on the controller. Press the gas until the solenoid clicks, right then you should read the full battery pack voltage between B- and M-. Continue to press the peddle down and watch the controller empty of voltage. This confirms the controller is powering up and putting out the voltage to the motor.

tonywebb76 · 06-27-2012, 06:36 PM

The voltage starts in the high 20's without pressing the pedal, and goes to full voltage as the pedal is pressed down.

05-24-2011, 08:11 AM	#1
carson398 Not Yet Wild Join Date: Nov 2010 Location: Prince George Va. Posts: 12	91 marathon controller does anyone know a simple way to test a controller? I think mine has gone bad. It runs for a while then slows downto a crawl then stops. I just put a new solinoid on it. Could it be the pot assembly? Or does it sound like the controller. Could it be the motor?

05-24-2011, 08:31 AM	#2
scottyb Happy Carting Join Date: Dec 2007 Location: Southern California Posts: 73,408	Re: 91 marathon controller Disconnect 2 wires from the pot to the controller stick the 2 test leads in the 2 wire connectors on the pot wires. Set DVM to 20k ohms and watch the meter as you depress the peddle. The reading should rise to 5-6k ohms.

05-24-2011, 08:33 AM	#3
scottyb Happy Carting Join Date: Dec 2007 Location: Southern California Posts: 73,408	Re: 91 marathon controller With the cart on jack stands: Do not rev the motor up hard while on jacks they can over spin and explode. Probably would be best to disconnect the motor leads from the controller first then test output. Check the power output from the controller by connecting the negative probe to the controller's M- terminal and positive to the B+ terminal. Press the accelerator and watch to see if the voltage increases. It should increase from a reading of 0 to the full voltage of the battery. If the motor is not turning, the problem may be in the directional switch or motor. The controller is bad and must be replaced if there is no voltage. I probably should mention controller test is done with at least one rear wheel jacked off the floor and key on, directional selector in forward. ~ test leads on B+ and M- should read 0v then push the gas and watch the voltage rise to full pack voltage?

05-24-2011, 08:33 AM	#4
shadowman The Last Moja Morani Join Date: Jan 2007 Location: jumping from cart to cart Posts: 8,975	Re: 91 marathon controller have you tested, load tested and checked the S/G on each battery? if not start there and check cables while your at it......................

05-24-2011, 02:27 PM	#5
carson398 Not Yet Wild Join Date: Nov 2010 Location: Prince George Va. Posts: 12	Re: 91 marathon controller I have checked batteries they are all good. thanks for all the posts

Today
BGW	Sponsored Links __________________ This advertising will not be shown in this way to registered members. Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

06-26-2012, 12:19 PM	#6
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6	Re: 91 marathon controller I'm having a similar problem. Does no voltage from M- terminal and positive to the B+ terminal mean the controller is dead for sure, or can this be caused by something else. My Pot is not reading 5-6k ohms either. Does one cause the other? 91 Marathon.
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6

06-26-2012, 11:38 PM	#8
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6	Re: 91 marathon controller The solenoid is clicking, and I'm getting 37.9v from B+ to B-. The pot is measuring 0-6k. I appreciate the help.
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6

06-26-2012, 11:58 PM	#9
scottyb Happy Carting Join Date: Dec 2007 Location: Southern California Posts: 73,408	Re: 91 marathon controller So far so good. Put test leads on B- and M- on the controller. Press the gas until the solenoid clicks, right then you should read the full battery pack voltage between B- and M-. Continue to press the peddle down and watch the controller empty of voltage. This confirms the controller is powering up and putting out the voltage to the motor.

06-27-2012, 06:36 PM	#10
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6	Re: 91 marathon controller The voltage starts in the high 20's without pressing the pedal, and goes to full voltage as the pedal is pressed down.
tonywebb76 Not Yet Wild Join Date: Jun 2012 Posts: 6

Similar Threads
Thread	Forum
Need A Controller cover for a Marathon	Electric EZGO
91 marathon controller to 48V	Electric EZGO
94 marathon controller question	Electric EZGO
Controller for 94 marathon needed!!!	Golf Carts and Parts
Controller Varistor 91 Marathon	Electric EZGO