92 36V Textron Marathon Series no go

[hmhsdad]

My neighbor just bought a 92 Ezgo Textron Marathon Series Serial # 677230 and Manuf Code C1992. I have two questions.
1st question from reading posts.

SERIES carts will have a shift lever like the dcs cart down by your legs, but it will NOT have a tow/run switch. Also the actual F&R switch is in the corner by the controller and there is linkage from it to the lever in the center.....

This cart has a shift lever behind the knees and I don't see a tow/run switch, however, I also do not see a linkage from the F&R switch to the controller. There are microswitches on the F&R Switch. Is this still a fleet(series)?

Things checked:
1. F&R microswitches have continuity.
2. Across battery pack is 36.5 volts.
3. Solenoid going to controller has 36.5 volts.
4. 36.5 Volts at motor from controller.
5. 250 ohm resistor at solenoid is continuous.
6. Solenoid de-energizes when gas pedal is released.

Any help getting it going will be much appreciated. I've read tons of posts, but none so far have helped me.

[Andy4639]

You are correct in the findings. The older Series carts the F/R was on the backside of the lever, the newer ones they moved over to the passenger side for battery clearances. If it's a passenger side one then it's a 94-95 or newer cart if it's in the middle it's before 94.
There is no linkage to the controller of any cart. You mean the F/R handle linkage right!

Cart jacked up on stands. Key turned off check micro switch on pot box see if it's showing cotinuity when you activate it with the pedal. If so then take the two small spade connectors off the controller that are white and black and check for OHM's with your meter. Press gas pedal and watch the ohms to see it climbs up to 5000 or so steady and no jumping around. 36.5 volts on the batteries is a sign of needing a charge the pack is almost dead. A 1/2 volt and it's done. 36 volts is dead.

[hmhsdad]

The switch on the pot box has continuity. I pulled the white and black spade connectors off the controller and with the gas pedal depressed it held a steady 2632ohms. It did not read 5000 ohms as you said. What now?

Thanks for the help.

[Fleck]

If the readings on the pot box wires started at 0 and only went to 2600 OHM. Try diconnecting the linkage from the arm on the pot box. Retest. The linkage may not be giving full movement of the arm and my need to be adjusted.

[hmhsdad]

Not sure of what I was doing earlier but the black and white spaded wires are reading 5.99 kilo ohms and holding steady. What to check now?

[Fleck]

Does it move at all or make any sounds? Is the 5.99 reading constant or is that at WOT. I've been told not to run the pot box over 5.1 because the controller will shut down.

[hmhsdad]

When checking pot box resistance it goes from 0 to 5990 ohms pretty quickly, but I am going from no throttle to WOT pretty quickly as well. Should I go 0 to 60 a little slower?

Secondly, when I check the hot side of the solenoid it shows battery pack voltage of 36 volts (I know it needs a charge). When I check the controller side of the solenoid it reads 25 volts. I thought it should only be 1-3 volts less than battery side. When I go WOT, I hear the solenoid pull in and the controller side immediately goes to battery pack voltage of 36 volts. This tells me that the solenoid is working at WOT.

I checked the motor tonight. There is continuity between A1 & A2 and also between S1 & S2. There is not continuity between any other combination of posts and I did not detect a lug grounded to the motor.

Thanks for the help....just trying to help a neighbor.

[qwerty77]

You see the blue wire right above those throttle wires? That's the controller enable, if at the moment it goes to B+ voltage the controller doesn't see something near 0 ohms, the controller will not start, this keeps people from "slamming" from reverse to forward. Like the other guy said, if it goes to high like 5.5K or higher that too will cause the controller to "kick out".
You can buy a replacement pot for about 20 bucks. Your not going to find one like it at radio shack. It's wire wound, with about a 20 degree dead band of 0 ohms.
To replace it you will need to remove the battery closest to it, disconnect the wireing, pay attention to the polarity of the two wires running to your F/R switch and the controller. (that's part of the voltage compensation/reverse slowdown feature) disconnect your throttle linkage, remove the three screws holding the box, theres a cable strap to the controller you will have to unmount, anyway, then take the throttle assembly inside, remove the 4 phillips screws and the throttle "arm" The rest is soldering, use rosin flux! It helps!!
Anyway once you got the new one in there you will want to "tweak it" using the slot at the end of the shaft so that as the thottle arm clicks the micro switch the resistance is right at 0 ohms and is starting to come up. Installed in the cart it should go smoothly from 0 ohms to about 5K

You also said you motor had 36v to it, but that shouldn't happen if that pot is bad.

[jauguston]

I am totally new to these things but let me tell you what I found on the '92 Marathon controller cart I recently bought in a "Won't run" condition. I ordered a repair manual from EZ-GO and started through the test procedure. Everything seemed to check out until I pulled the blue wire spade connector off of the controller and cleaned it with some contact cleaner with a Q-Tip like the book said to do. I reinserted the connector that I had previously tested as having power and away it went. That spade on the controller was corroded.

Jim -- Learning as I go.