Intermittent F+R Problem

[konakid]

I am very new to electric golf carts, but not to troubleshooting and fixing most things. But this is a brand new area for me, so trying to understand a lot of the terms I came across searching for an answer was a challenge.

I just came home with a used 36 volt EZGO. I don't have all the specs, but you may not need them just to get me pointed in the right direction with a fix. A photo is attached nonetheless

Hopefully this is a simple diagnosis because it is intermittent - either working perfectly fine in forward and reverse, or not working at all. The F+R switch is a three position toggle on the dash - photo attached.

I hear what I assume is the solenoid under the set when switching the toogle. Sometimes it then goes forward or reverse perfectly. But about half the time I have to switch it back and forth several times to get it to work. But I always seem to hear the solenoid. I can't hear anything differently when I switch and it works, or when I switch and it doesn't work.

I am hoping it may just be the switch. Can anyone give me any feedback on what to do first? I would like to pull that switch out and check the contacts, but I am not even familiar with how to remove it. I don't see any easy way to get behind the dash there. The nuts don't look as if they can be removed. Can I pop the switch out?

[scottyb]

The key switch plate on your PDS Ezgo cart is held in with 2 push rivets. These rivets are designed for one time use. You can buy replacements from shopezgo.com or use screws or pop rivets to reinstall.

If you remove the switch you can test it for continuity, or you can test it at the signal wires at plug J1 shown below. Continuity test would be between pin 1&2 and 1&3 in F&R

I have seen these switch terminals corrode and I have seen the switch go bad.
Good Luck

[konakid]

Thanks ScottyB - As an experienced active participant in some other forums where I am an "expert," I know the reluctance I fell sometime to help a newbie who obviously knows absolutely nothing about the subject matter.

But I have been doing my homework to try and understand this issue further. So I understand this may not be a simple problem. But if anyone is willing to help after I present the following more complete information, any info will be appreciated as I try to track this down.

Here is what I have come up with. I have an Alltrax NCX controller (this is a PDS cart). Visually the controller, all the wires, and connections look great - no indications of any heat damage or loose connections - none.

I have to assume the switch is okay because every time (without fail) when I flip it - I see the light on top of the controller come on, and I hear a click I assume is the solenoid. Now here are the clues that may mean something to the informed.

When the switch is flipped to F or R the green light flashes 4 times, then stops, then a red light flashes three times repeatedly. It does this almost every time I switch back and forth. And, of course, when the red light is flashing the cart won't move.

But, if I flip the switch it a rapid and quick motion from F to R and back again, sometimes the light stays solid green and the cart operates flawlessly - as long as I don't turn the key off, or flip the switch again.

I hope this is a smoking gun that can help someone help me.

[CCFanatic]

Direct from Alltrax's website:

4 Green LED flashes = EZ-GO inductive (ITS)

3 Red = HPD. Throttle hasn't gone to zero during this power on cycle

[konakid]

Thanks for the super quick reply CC - now if you would be so kind as to fill in a couple of blanks for me. I am hoping we are getting somewhere.

Are the four green flashes normal? It does this every time. But then it either goes to the red flashing, or goes to the solid green and the cart works. So are the four green flashes a normal process, or should it just go immediately solid green?

And something else. I seem to be able to fairly consistently get it to go solid green if I flip to F or R and then rapidly go to back and forth 2 or 3 times between F and R as quickly as I can flip while it is doing the four green flashes. Then it will stay green. And if I am in R or F and the green light is on - if I flip super fast, it seems to stay green and work for the other direction. But if I go a little slower to neutral and then the other direction, it resorts back to the red flashing.

But - if this is a throttle not going to zero issue - what do I need to do to correct that? Is that a linkage adjustment?

And - super dumb question - is this the diagnostic mode that I have read about? Should it even be in this mode?

[CCFanatic]

Originally Posted by konakid

Thanks for the super quick reply CC - now if you would be so kind as to fill in a couple of blanks for me. I am hoping we are getting somewhere.

Are the four green flashes normal? It does this every time. But then it either goes to the red flashing, or goes to the solid green and the cart works. So are the four green flashes a normal process, or should it just go immediately solid green? The four green flashes are normal. That indicates that the controller is programmed for the ITS throttle (Which is what you have). When functioning normally, it will flash four times green and then solid green

And something else. I seem to be able to fairly consistently get it to go solid green if I flip to F or R and then rapidly go to back and forth 2 or 3 times between F and R as quickly as I can flip while it is doing the four green flashes. Then it will stay green. And if I am in R or F and the green light is on - if I flip super fast, it seems to stay green and work for the other direction. But if I go a little slower to neutral and then the other direction, it resorts back to the red flashing.

But - if this is a throttle not going to zero issue - what do I need to do to correct that? Is that a linkage adjustment? If you have the ControllerPro software (If you don't, it is a free download on Alltrax's website), make sure that HPD switch is disabled and recalibrate throttle output for 0

And - super dumb question - is this the diagnostic mode that I have read about? Should it even be in this mode? No, the four red flashes is not diagnostic mode. That is something completely different

See above

[JohnnieB]

CCFanatic is right about the error code.

The key has to be ON and a direction selected for the controller to power up and if it sees a throttle signal less than 10V (10V = no throttle 6V = max throttle) or that the contacts of the pedal microswitch are not open at power up, it goes into the HPD mode.

The diagnostic mode you've read about does not apply. You do not have a stock PDS controller (Curtis 1206MX). Instead you have an aftermarket Alltrax NCX, which is not user programmable like the DCX family of controllers are.

Four Green flashes means the controller is set to an ITS throttle type, which your cart has. Four flashes and then to steady Green is normal. (Other throttle types would have a different number of flashes before going to steady green)

The controller powers down she you change directions, which rests the computer and looks for the proper power up conditions again (HPD). The is a bit of residual energy, so you are probably getting from F to R or R to F faster than the controller shuts down.

There are several things that can cause a HPD error, but mostly it is either the pedal microswitch, or the ITS sensor, or bad contacts in a plug, and there are four sets of them in the wires between the controller and the pedal box under the floor board.

Since you can flip the F/R switch fast enough not to get the HPD error, my guess is a bad or maladjusted Pedal microswitch.

When the green light is on steady and your foot is off the pedal, does the cart try to move?

When you take you foot off the pedal, do you hear the solenoid click. It may not click the moment you take your foot off the pedal, but usually within a second or so.

The controller controls the solenoid, the pedal switch just tells the controller what to do.
When the controller powers up, the solenoid may click, but it drops out a few seconds later.
Then it clicks almost instantly when the pedal is pushed and drops out (eventually) when the pedal is released.

If it clicks when the controller powers up and stays clicked, the pedal switch is most likely the culprit.

[JohnnieB]

Originally Posted by CCFanatic

See above

You are quicker on the keyboard than I am.

The NCX isn't user programmable and recalibrating the throttle zero isn't an option in the DCX. You do have that option with the SPM family of controllers.

Throttle up rate and down rate are programmable and the throttle response curve is selectable in the DCX.

[konakid]

JohnnieB - that is extremely valuable information, and I am confident it will get me on a path to fix this. I will have to go through a few cycles and "tests" before I can give you definitive answers to the questions you have asked.

But while screwing around and waiting for any responses I came across this clue that may tell you exactly what it is. And I think it points to what your guess was.

I gave the "gas" pedal a really good jiggle. And then turned the key and flipped the switch. It went to solid green 10 times in a row when switching back and forth from F to R. I didn't pay attention to when the solenoid or clicking occurred. I was just pleased I had a green light and it would go. So I am assuming I don't need to worry about the order of clicking, etc. and can concentrate on something directly related to the pedal. Correct.

Does it sound to you like the pedal micros with?

I will try to get the info on the order of clicking if you still think that is important. But I can tell you that, No - the cart does not try to move when the light is steady and my foot is off the pedal.

While waiting your reply, I'll be looking for the pedal switch, and any adjustment. Can you point me in the right direction on that if I can't find it. Is that something I will have to access from underneath - I don't have a jack, but I do have a set of those little ramps used for oil changes.

OOPS - I missed CC's responses before answering - but it appears as if I might need to recalibrate the throttle switch. Which I have no idea how to at this point. But before I try to figure out how to do that - does the fact that I can rattle the pedal and it then works indicate it may be a mechanical adjustment???

[scottyb]

I would be doing a physical inspection of the ITS plunger operation and micro switch. It could be as simple as replacing the ms or re aligning it on the plunger.

Remove driver side rocker panel, lift the floor mat, remove the pedal box cover.