EZGO Marathon Issues with Reverse

[Rodney Hardegree]

I recently purchase an 80s era EzGo Marathon and replaced the controller. It runs fine in forward, but won't go in reverse. The reverse alarm works fine. When you step on the peddle while in reverse the solenoid clicks, but nothing else would happen. I jacked up the rear end and put it in reverse and pressed the peddle and it spun the tires in reverse, so I thought it had started working, but with tires on the ground it does nothing. While jacked up and running in reverse I can grab a tire with my hand and stop it from spinning, while the opposite one continues to spin.
Any help would be appreciated!

[Andy4639]

Sounds like the hubs have either stripped out are the input shaft has gone bad inside the rear end housing. I have replaced one input shaft in 20+ years of working on them. But it was doing as you described.

[scottyb]

None of the 80s Marathon had electronic speed control so your cart has been updated or it is not from the 80s. Regardless, the early Marathons had a throttle sending potentiometer which had 2 pairs of wires. One pair went to the controller and gave a pedal position signal of 0-5000Ω. The second pair went to the reverse micro switch on the F&R. When the selector was in R the second pair was connected one wire to the other by the switch. This sent a signal to the pot which reduced the signal to the controller by 50%.
Remove one of this pair of reverse wires from the F&R. Put tape on it and test the cart. Any change?

[Rodney Hardegree]

I was told it was an '85 Marathon, but was also told a number of lies when I purchased it. Anyway, it has a Curtis 1204-009 controller. I attached some pics of the controller and potentiometer and the F/R switch. I just went out in the dark and identified the two sets of wires. There's a white and black set going to the controller and another white and black to the F/R switch box. Does it matter which one I disconnect from the F/R switch box (white or black)? Thanks again. I won't be able to test until tomorrow weather permitting.

[Rodney Hardegree]

Thanks for the help. Turned out to be an intermittent connectivity issue on the F/R switch. I cleaned the connectivity points and reverse now works. I sometimes have to move the switch a little for connectivity to happen on the reverse side.

[yurtle]

If it's like mine - dunno 'bout Marathons - the FNR is mounted on a bracket that has slots where it connects to the frame, allowing you to adjust how far it rotates in both directions. I placed my FNR exactly halfway between F and R and then slid the assemble left and right until my handle was exactly in Neutral.

You also may want to tighten the center nut, to avoid a loose connection, which can result in FNR meltdown.