Ezgo throttle signal testing made easy
Wait ! - What is the throttle signal?
The throttle signal tells the speed controller how fast you want to go. The speed controller does this by limiting the motor's access to the battery bank (amperage storage).
The Ezgo Marathon. In this cart the go pedal is connected to a potentiometer. This particular pot (short for potentiometer) has a signal range of 0-5000 ohms. This signal is often represented as 0-5kΩ and is easily tested using the ohm setting on your multi-meter.
Simply unplug the the 2 signal wires from the controller and plug your test leads in. Work the pedal up and down a few times to establish (average out) the range reading. A typical reading will be under 200 ohms with the pedal up and not over 5800 with the pedal down. Further out of range may cause problems. These units are susceptible to water damage. If wet they can be restored with a hairdryer.
There are 4 wires (2 pairs) coming from this POT. One pair carries the go pedal signal. The other pair goes to the F&R switch reverse micro switch. When the cart is in reverse this switch closes connecting the 2 wires which results in a 50% reduction in the throttle signal or 0-2500 Ωs.
1994.5 and up Medalist and TXT use the induction throttle signal commonly known as ITS. This is a voltage system where the controller puts out the base throttle voltage and the pedal induction device (under the floor) reduces the signal voltage more and more as the pedal is depressed. This device is also subject to interference by water, see hair dyer tip above.
Below is the test procedures and results for all Alltrax controllers.
OEM Curtis controller. tests attached below. Results should be as follows:
DCS and Series carts have a signal range of 0.4-0.6v through 1.5-1.7v
PDS carts have a signal range of 1.0v (+/- 0.3v) through 2.7v (+/- 0.5v)
Throttle Voltage Check With Alltrax Controllers
To verify that the Inductive Throttle Sensor (ITS) is working correctly with the Alltrax controller you will need to measure the throttle inputs voltage at the controller and also at the ITS throttle to make sure they have the same readings.
Make sure the Cart is on secure jack stands so you can safely run the wheels. DO not over rev or hold high rpm. Motor damage will occur. Don't short between pins when doing measurements, you could damage the controller.
Alltrax DCX & NCX controllers, you need to pull the 10 or 6 pin connector back just enough to expose the pins to measure them. Make sure not to short any of the pins. With the key On, tow run On and the F/R in forward postion measure the voltage between the two throttle pins (see pictures below). You should see 10 volts. Press the Pedal down to the floor, full throttle and you should see 6 volts.
Alltrax SPM, SPB, AXE & NPX controllers, measure the voltage between the two throttle pins (see pictures below) with the key on and the peddle depress just enough to active at the foot switch. You should hear the solenoid close at this time and have a lit LED light. You should see 10 volts on the throttle pins. Press the Pedal down to the floor, full throttle and you should see 6 volts.
Out of range
If you are measuring 12 volts it is typically a bad ITS unit, and if you get 14 volts there is often a broken wire running to the throttle.
SPM-**** EZ Pins
SPM model Ezgo controllers the throttle pins are 2 & 3 on the left set, or 1 & 2 on the smaller pins on the right. Choose one set or the other to test. Note that for SPM controllers and ITS throttles you must use the included noise filter.
SR Control : B- to the small White Wire (usually on J4) with the solenoid just engaged it should be reading about 8-10V and at full throttle 6-5V, if you measure between J4 and J5 you should see 10-12V being output from the controller.
XCT Control : B- to the small white wire (Pin 1 on DCS carts, and the small white wire in the 4pin plug on PDS carts) just sitting there with everything powered should be 8-10V and at full pedal press 6-5V. Measuring between the black and white wire while the controller is powered up should result in a standing voltage of 10-12V
Resistor and Diode installation tutorial
MOTOR RUN TEST
This method requires less than full voltage applied briefly to the motor while it is installed in the cart and the rear wheels are off the floor or ground. Use 12-18 volts. You will find this voltage using your test meter between the main - post on battery 6 and the positive terminal on battery 3 or 4 depending upon 6 or 8v batteries used.
NOTE - when the voltage is applied to the motor as shown there will be a spark at the final connection and the motor should lurch to life... hence the lower voltage recommended. Do not let the motor run for more than a few seconds. Because there will be a spark it is recommended to utilize a switch like a common battery disconnect to make the final connection. Simply touching the final connection to the motor or battery will result in a damaged motor or battery terminal.
Solenoid not working
How to verify the solenoid is actually working?
Remove the pre-charge resistor from the big terminals.
Put the voltmeter black (common) on battery main (-) and the red lead on the solenoid big terminal with the battery Main (+) cable on it
The voltmeter should read the same as the battery pack here.
Now press the pedal so the solenoid clicks and move the red lead to the other big solenoid post = this should also now read the same as the battery pack.
Now release the pedal and the power should disappear from the second big post.
Repeat the test several times to see that the solenoid is consistently closing (power at both big terminals) when it clicks and opening (power at one big terminal) when the pedal is lifted.
Solenoid not clicking
The solenoid makes a click sound when it activates or closes and another click when it opens. Power flows between the large posts when the solenoid is closed.
Solenoid activation requires battery pack voltage is present and readable with a voltmeter between the 2 small terminals. It takes + on one small terminal and – on one small terminal to activate the solenoid.
The solenoid should only be closed when the cart is running. Never leave the solenoid closed (activated) when the cart is not in use.
2. Does the solenoid click when you try to go?
If no, there is a control circuit problem or a failed solenoid
If yes, you have a problem in the supply side of the system.
Either way here the solenoid could be the cause of the problem. There are 2 ways the solenoid can fail. It can fail to activate when asked to so so (a control side failure) or it can fail to engage the high amperage contacts (a supply side failure)
I would first make a quick inspection of all the cart wiring to rule out the possible cut wire or bad connection. Visually check then pull and twist the cable ends to insure they are intact.
Here are a few tips that will help you approach common problems. For more in depth help go to http://www.buggiesgonewild.com for community tech support. I will see you there.
The most common complaint is the cart wont go. There can be several causes. I will list only the most common simple causes.
It is important to understand there are 2 sides to any DC drive system.
There is a low amperage side which includes all the small wires. The current in these small wires control the cart telling when to go and how fast. We call this the control circuit.
The high amperage side supplies the power to the motor. This supply side includes all the big battery type cables and current control components like the solenoid, controller, and (in series carts only) the F&R. For sepex carts the F&R is part of the control circuit.
In summary; small wires = the control circuit
and big wires or components = the supply circuit
1. Check battery voltage. This is the life blood of the whole system.
The battery pack should always be above 36v for 6/6v batteries or 48v for 48v systems.
Put the meter on the pack and try to go.
If the voltage drops significantly (6-8v) you have a battery problem
If no voltage drop you have a connection or component failure.
Troubleshooting Aids & Tips
MOTOR TEST Ω ohms
This method requires checking the windings with an OHM meter
Check ohms between a1 and a2 .3 to 1 ohm.
check f1 to f2 -1 to 2 ohms.
check a1 to f1 should be open.
check f1 to casing of motor s/b > then 5 ohms.
1. Every golf cart should have an in dash digital battery meter. This is the most valuable addition you can make to the cart.
2. All golf carts are not the same. Some are designed for utility and some for speed.
Series carts are utility carts. They excel off the road. Sepex carts are NEV type vehicles.
3. Go to the upgrade suggestions page to learn how to identify series and sepex carts.
4. Respect the voltage and amperage present in every cart. Never let children "help" you work on the cart. Become familiar with and learn to identify positive and negative current.
No frame ground or negative (-) is permitted on any electric golf cart.
5. Every electric cart owner should own and learn to use a multi-test meter or DVM.
See the short video below about what to buy and how to use it.
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