PDS/Key Switch/Won't Go

[HOOTIE]

Hello all, I'm having a problem with my PDS cart that had last year as well. Changed the solenoid which corrected problem until now but has came back. Also have new batteries put in last year(36v-measuring 6.9 at each battery). Also have issue with the key switch, or shall I saw the key switch isn't having an effect on it? Can't remember if it was before or after problem with cart not going, but I was able to run cart without switch even being turned on. Are these problems related? I have key switch completely removed with no wires attached and it will still 'try' to go. I get a slight surge. Any suggestions on what this might be?

[JohnnieB]

Does the solenoid click when the pedal is pushed?

[HOOTIE]

Yes, it does click. I measured voltage across the solenoid when the pedal is pressed and it holds for a couple seconds until it 'un'-clicks.

[JohnnieB]

Does it un-click while the pedal is still being pushed, or are you saying it stays clicked for a few seconds after the pedal is released?

-----------
A PDS is a fly-by-wire drive system and the controller controls the solenoid operation as well as the direction the motor rotates, the armature amps, the field amps, the beeper and regen braking.

If the turning the keyswitch off does not prevent the cart for operating, either the keyswitch has bypassed or the controller is bad.

Attached is a schematic of a PDS drive system with the solenoid activation circuit highlighted.

All the wires highlighted in red have to have full battery pack voltage on the, for the solenoid to click.

[HOOTIE]

Sorry I never got back to this thread but I have been away from the beach and the cart for a while and can't look at it right now. I do need to get this thing fixed because we have some renters coming up and one is a pregnant girl and they really need to use it. As I can't diagnose it right now, I just wanted to ask could this be micro switch related? The symptom I really want to figure out is that the cart would go without the key being turned and even with the key assembly wires completely disconnected it would go. I have had two solenoids go bad so I am suspecting whatever is allowing the car to run without the key is also killing the solenoids. I do remember hearing the solenoid click when the pedal was depressed and then unclicking a couple seconds after letting off the pedal. This makes me think solenoid is not 'welded' stuck.

[scottyb]

You could be right. If the cart runs without the keys switch (ks) then it is possible the solenoid is energized all the time and this would cause the solenoids to fail after some time.

This system is designed with the ks in the primary + current path. If disconnecting the ks does not stop the operation we can conclude that like johnnie said the control has failed in some unusual way that allows power to the solenoid all the time or more likely the solenoid is miswired. This may have occurred during replacement. When you get to the cart, post up some pics of the solenoid install.
Another possibility may be a welded solenoid. A likely occurrence if the cart has stock components and is operated under heavy loads or in sand (typical renter operation)
In any case I would certainly bring a heavier replacement solenoid like MZJ200 when you go to see the cart.

[HOOTIE]

Originally Posted by scottyb

You could be right. If the cart runs without the keys switch (ks) then it is possible the solenoid is energized all the time and this would cause the solenoids to fail after some time.

This system is designed with the ks in the primary + current path. If disconnecting the ks does not stop the operation we can conclude that like johnnie said the control has failed in some unusual way that allows power to the solenoid all the time or more likely the solenoid is miswired. This may have occurred during replacement. When you get to the cart, post up some pics of the solenoid install.
Another possibility may be a welded solenoid. A likely occurrence if the cart has stock components and is operated under heavy loads or in sand (typical renter operation)
In any case I would certainly bring a heavier replacement solenoid like MZJ200 when you go to see the cart.

I upgraded to the heavy duty solenoid recommended by folks on here a few years ago when I upgraded the controller. It ran for a few years before arriving at the condition of being able to go without the key being turned on. That solenoid died last year so I replaced it with what I could get my hands on from the guys at Ocean Lakes last year. It was supposed to be heavy duty as well but certainly didn't look like the one it replaced. I really suspected welded solenoid but the clicking on and off made me believe that wasn't the actual problem. I forget exactly what I measured on voltage but I could see voltage being applied and deactivating when I put the meter on it last time I was down trying to diagnose the cart. I'm not the smartest with the wiring diagram so I probably need to be told exactly where to test with the meter and what readings I should be getting.

[scottyb]

I have seen welded solenoids make clicking noise but not disengage the welded contact bridge.

[HOOTIE]

Originally Posted by scottyb

I have seen welded solenoids make clicking noise but not disengage the welded contact bridge.

That's probably the first thing I'm going to throw at it when I go back. Should I go ahead and buy a micro switch as well since it looks like they aren't all that expensive? Also, after doing a little research, it seems like some folks with a similar issue have found it ended up being a bad wiring harness? Would this be the controller harness?

[scottyb]

It's impossible for me to say from here. I need a ticket to this island paradise and a weeks accommodations.