Pds starting and stoping abruptly

[kgsc]

Bad solenoid can cause this.

[JohnnieB]

What make/model solenoid?

[georgia088]

I have my suspicions the solenoid is bad/going bad too.... I just don’t understand why it works correctly some and then cuts down. I just wouldn’t think a solenoid would do this. I would think once it is energized it either internally connects those large posts or it doesn’t. I wouldn’t think it would connect 50%. But I’m obviously not smart enough to figure this out with out y’alls help. I really appreciate any and all help!

[georgia088]

Not sure about make/model. I’m pretty sure I ordered it from Scotty with the controller. I’ve had/worked on a couple of carts, I can’t remember. I will have to check.

[JohnnieB]

There are many solenoid designs and solenoids have a finite lifespan. In other words, they wear out.

More correctly, a solenoid is a electromechanical actuator and what is called a solenoid around here is actually a contactor, which is a relay that is designed to carry higher amps.

The contact closure is not truly on and off because the contacts bounce a few times before they come to rest and arcing occurs during the bouncing. The contact bounce period on the solenoid I'm using is 3ms.

Attached are images of the stationary (Attach-1) and moving contacts (Attach-2) on a stock EZGO PDS solenoid. Since the circular contact can rotate, the contact area can change, so the contact resistance can vary from closure to closure.

Of course, with an aftermarket controller, you might have an aftermarket solenoid also.

[JohnnieB]

Originally Posted by georgia088

Not sure about make/model. I’m pretty sure I ordered it from Scotty with the controller. I’ve had/worked on a couple of carts, I can’t remember. I will have to check.

If you got the DCX for Scotty, I'm pretty sure he sold you a decent solenoid to go with it.

When did you get the DCX?

[georgia088]

I love learning about this stuff, but I’m not very smart. So, I have to ask questions.

So you are saying that when the pictured solenoid is activated it pulls the donut looking contact toward the big posts copper points, but as it wears it may not make “as good a connection in some places of that “donut” as others? So, it could be allowing more amps through it during some activations than others?

Thanks for helping!

[JohnnieB]

Originally Posted by georgia088

I love learning about this stuff, but I’m not very smart. So, I have to ask questions.

So you are saying that when the pictured solenoid is activated it pulls the donut looking contact toward the big posts copper points, but as it wears it may not make “as good a connection in some places of that “donut” as others? So, it could be allowing more amps through it during some activations than others?

Thanks for helping!

Yes.

BTW, the donut is inverted so the arcing damage can be seen.

Of course, you may have a different solenoid design.

[georgia088]

Awesome info. I will see about replacing solenoid. Would this be a cause of the low voltage error? Like I said, it goes away when I place the cable on the input side of solenoid.

Why does the high amp cable need to go on output side? The cart still will not run without the solenoid activation.

[JohnnieB]

Originally Posted by georgia088

Awesome info. I will see about replacing solenoid.

1. Would this be a cause of the low voltage error? Like I said, it goes away when I place the cable on the input side of solenoid.

2. Why does the high amp cable need to go on output side? The cart still will not run without the solenoid activation.

1. It could be the cause of the error and the error going away when the solenoid's contacts are bypassed with a jumper is an indicator that it is.

2. If you bypass the solenoid's contacts by placing the controller side cable on the battery side terminal along with the heavy gauge cable from the battery, you've bypassed the solenoid's contacts and the battery pack is connected to the motor and controller 100% of the time. It is true you still have to have the Run/Tow switch in Run, a direction selected on the F/R switch, the key ON and press the pedal to get cart to move, but if the if the controller fails (MOSFETS short), you cannot stop the cart and if the motor or controller start smoking and sparking, you cannot disconnect the battery pack by lifting your foot off the pedal and you'll be culpable for any and all damages caused.