89-94 ez-go

Mooncarter · 05-27-2018, 06:24 PM

Hey guys, I have a 1999 Melex 625. Has same controller, other electrical components as 89-94 EZ-GO.

Solenoid clicks but no go. Cart runs with M- and B- jumped on controller forward and reverse. All micro switches seem to be functioning.

I have very little EZ-GO/Melex experience. Should I assume the controller is bad? If so that's OK just have to replace it but I would hate to replace it only to be back to square one.

Thanks for all replies!

yurtle · 05-27-2018, 06:50 PM

When it runs, does the throttle control the speed? If the solenoid is clicking, you can rule out all the reed switch, key switch, and all microswitches. If it runs forward and reverse, you can rule out the FNR.

Mooncarter · 05-27-2018, 06:57 PM

I did not try it, but I think the M- to B- jump test causes the cart to run WOT. At least it does on a Club Car. Should I try again and test that? I think I just pressed it to the floor.

JohnnieB · 05-27-2018, 07:03 PM

Quote:

Originally Posted by Mooncarter

Hey guys, I have a 1999 Melex 625. Has same controller, other electrical components as 89-94 EZ-GO.

Solenoid clicks but no go. Cart runs with M- and B- jumped on controller forward and reverse. All micro switches seem to be functioning.

I have very little EZ-GO/Melex experience. Should I assume the controller is bad? If so that's OK just have to replace it but I would hate to replace it only to be back to square one.

Thanks for all replies!

Jumping B- to M- effectively eliminates the controller and connects the full battery pack voltage to the motor (via the F/R switch) when the solenoid clicks.

Could be a bad controller, but could also be a bad throttle or a bad wire between one of the small terminals (coil) on the solenoid and the controller.

The controller doesn't power up until solenoid clicks and same voltage from pedal switch the makes solenoid click is also fed to the KSI input on the controller. If the wire between solenoid coil and controller KSI input is bad, the controller isn't powering up, so its a no-go.

If the controller is powering up, but the throttle isn't telling it to pass amps to the motor, it is a no-go.

You need to make some voltage readings to determine what the failure is.

Mooncarter · 05-27-2018, 07:12 PM

Thanks guys.

Johnnie B I thought the controller was bypassed during that test, thanks for the clarification. Also, I left out the fact the resistor across the solenoid large posts was broken on one end so I just removed it until I can get another. I know not good but would not cause no go right?

After working on Club Cars, this throttle is totally strange to me.

yurtle · 05-27-2018, 07:25 PM

In the short term, you can run it without the resistor. Follow the cable that runs from the throttle box to the wiring harness, usually located between the FNR and the controller. It has a 4 wire Molex connector. These often cause probems, due to corrosion. Unpug it and spray contact ceaner, then replug/unplug/replug several times. Mine got so annoying, I finally cut the connectors off and soldered and heat-shrinked the eight wires (4 on each side).

Mooncarter · 05-27-2018, 07:38 PM

Quote:

Originally Posted by yurtle

In the short term, you can run it without the resistor. Follow the cable that runs from the throttle box to the wiring harness, usually located between the FNR and the controller. It has a 4 wire Molex connector. These often cause probems, due to corrosion. Unpug it and spray contact ceaner, then replug/unplug/replug several times. Mine got so annoying, I finally cut the connectors off and soldered and heat-shrinked the eight wires (4 on each side).

Pretty sure this cart does not have that. I think those wires are all connected via spade connectors with clear plastic slid over them.

Mooncarter · 05-28-2018, 04:43 PM

Quote:

Originally Posted by JohnnieB

Jumping B- to M- effectively eliminates the controller and connects the full battery pack voltage to the motor (via the F/R switch) when the solenoid clicks.

Could be a bad controller, but could also be a bad throttle or a bad wire between one of the small terminals (coil) on the solenoid and the controller.

The controller doesn't power up until solenoid clicks and same voltage from pedal switch the makes solenoid click is also fed to the KSI input on the controller. If the wire between solenoid coil and controller KSI input is bad, the controller isn't powering up, so its a no-go.

If the controller is powering up, but the throttle isn't telling it to pass amps to the motor, it is a no-go.

You need to make some voltage readings to determine what the failure is.

This controller has 3 small tabs. What is the KSI input?

mgray70 · 05-28-2018, 07:21 PM

Pin 1 is the KSI. Should be pack voltage when the solenoid clicks. Pin 2 and 3 are the throttle wires. Unplug them and use your DVM to test resistance between the two wires. With it set to ohms you should start with 0 ohms with pedal up and 5000 ohms with pedal down.

Quote:

Originally Posted by Mooncarter

This controller has 3 small tabs. What is the KSI input?

Sent from my SM-G930R4 using Tapatalk

Mooncarter · 05-28-2018, 07:28 PM

Thank you Mr. Gray. Does it matter if - or + goes to which wire?

05-27-2018, 06:24 PM	#1
Mooncarter Gone Insane Join Date: Oct 2016 Location: Richmond, VA Posts: 14,214	89-94 ez-go Hey guys, I have a 1999 Melex 625. Has same controller, other electrical components as 89-94 EZ-GO. Solenoid clicks but no go. Cart runs with M- and B- jumped on controller forward and reverse. All micro switches seem to be functioning. I have very little EZ-GO/Melex experience. Should I assume the controller is bad? If so that's OK just have to replace it but I would hate to replace it only to be back to square one. Thanks for all replies!

05-27-2018, 06:50 PM	#2
yurtle Gone Mad Join Date: Oct 2009 Location: Buford, GA Posts: 8,988	Re: 89-94 ez-go When it runs, does the throttle control the speed? If the solenoid is clicking, you can rule out all the reed switch, key switch, and all microswitches. If it runs forward and reverse, you can rule out the FNR.

05-27-2018, 06:57 PM	#3
Mooncarter Gone Insane Join Date: Oct 2016 Location: Richmond, VA Posts: 14,214	Re: 89-94 ez-go I did not try it, but I think the M- to B- jump test causes the cart to run WOT. At least it does on a Club Car. Should I try again and test that? I think I just pressed it to the floor.

05-27-2018, 07:12 PM	#5
Mooncarter Gone Insane Join Date: Oct 2016 Location: Richmond, VA Posts: 14,214	Re: 89-94 ez-go Thanks guys. Johnnie B I thought the controller was bypassed during that test, thanks for the clarification. Also, I left out the fact the resistor across the solenoid large posts was broken on one end so I just removed it until I can get another. I know not good but would not cause no go right? After working on Club Cars, this throttle is totally strange to me.

05-27-2018, 07:25 PM	#6
yurtle Gone Mad Join Date: Oct 2009 Location: Buford, GA Posts: 8,988	Re: 89-94 ez-go In the short term, you can run it without the resistor. Follow the cable that runs from the throttle box to the wiring harness, usually located between the FNR and the controller. It has a 4 wire Molex connector. These often cause probems, due to corrosion. Unpug it and spray contact ceaner, then replug/unplug/replug several times. Mine got so annoying, I finally cut the connectors off and soldered and heat-shrinked the eight wires (4 on each side).

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05-28-2018, 07:28 PM	#10
Mooncarter Gone Insane Join Date: Oct 2016 Location: Richmond, VA Posts: 14,214	Re: 89-94 ez-go Thank you Mr. Gray. Does it matter if - or + goes to which wire?