frame voltage

[sonnysmith]

I have a 2007 EZ GO pds 36 volt golf cart
I have voltage on battery hold down rod of 31 voltage from neg. post to hold down rod. I have taken all wiring off the battery post except , wire to solenoid from pos. post and one wire from neg. post to neg. on controller.
Now i have voltage to the hold rod, 23 volts. I took the black and white wire off controller, no change. When I remove the A1 wire from the controller to the motor the voltage goes away. Can this be a motor problem or controller or both. It's a new one for me.

Thanks to anyone that can help.
Sonny

[Golf cart guy]

Ive seen this before.
generally its in the motor.
However, you need to make sure the tops of the batteries are clean and dry. You don't have pack voltage going to the frame, so that's good.

[cgtech]

Carbon dust in the motor.

[rib33024]

Here's some info. This gets talked about a lot here


http://www.buggiesgonewild.com/elect...t-voltage.html

http://www.buggiesgonewild.com/elect...ormal-not.html

http://www.buggiesgonewild.com/elect...age-frame.html

[sonnysmith]

Thanks all. I will do some more checking.
Just don't want to burn anything down.

Sonny

[yurtle]

My experience was that the voltage was there, but checking it with an ammeter and a light bulb indicated there was no Oomph (a technical tterm). behind it. Other causes could be slightly conductive electrolyte on the tops and sides of the batteries, and possibly, though I've never proven it, capacitive coupling between the batteries' plates and the cart frame.

You only mentioned the battery hold down posts, but they are connected to the frame (depending on how bad the coating is, so have you tried measuring to other frame parts?

[sonnysmith]

yes sir,I checked frame and it had the same voltage . The way I found it, i was putting on the cables and touched the hold down rod and a spark.
Some have asked about batteries, they are brand new.
Now let me ask one more question. When I check the voltage neg to hold down rod. I have 18.6 volts . when I check pos post to same hold down rod, I have 1.2 volts. When checked with cart running, both of these voltages go to zero. Does this tell you anything?
Next Question. Will a fuse on the neg post give me a little more protection from a melt down?

Thanks all for your reply.
Sonny

[yurtle]

I'm no expert, but I'd say no voltage differential when running means you are fine. Just to test it, connect a light bulb - any voltage from 6 - 12 - between the two locations giving you the highest voltage. I suspect you won't see anything.

[Raystar57]

Originally Posted by cgtech

Carbon dust in the motor.

I vote for this.
Remove the motor wires and insulate the terminals.
Does the ghost voltage still exist?

[yurtle]

Originally Posted by Raystar57

I vote for this.
Remove the motor wires and insulate the terminals.
Does the ghost voltage still exist?

I agree it's a possible source, but, the motor would "leak" when it had voltage going to it. The OP indicates frame voltage when it's not running = no voltage going to motor, and I assume nothing going to the controller. He reads no frame voltage when it's running.

I gave up figuring out mine. My next move was to remove interconnecting cables, but that reeks of effort, and it wasn't causing me any problems. Like I said, I connected an ammeter - which is a direct short - and got almost no amperge.