Will not hold speed

[forr33l]

So I have found some really great information off of this forum in the past couple weeks for a Club Car DS (AA0314-270381) that was given to me by a family member. When I obtained the cart it needed new batteries so I went ahead and replaced them. After a good first charge (all batteries were at 9.2V), on it's first test run it ran great, reached max speed, until I let off the petal to come to a stop. When I reapplied my foot to the pedal the cart would not go faster than 3 mph. If I were to wait 5 minutes or so it will do the same thing, start fast then crawl. Supposedly, even before I changed the batteries the cart would start to slow down with the pedal fully engaged but if you quickly let off the pedal and push it back down it would reach full speed again. (this no longer works)
I pulled out my meter and tested the potentiometer, the resistance was a smooth increase in ohms as I pressed the pedal down and released it.
Next I checked all my connects and replaced the ones that seemed corroded from the controller, solenoid, FNR switch and potentiometer. Still having the same issues I started to try and diagnose the controller. Everything I have read leads me to believe that the controller is something that usually fails catastrophically. Is there any truth to that? I have also read that since that cart is a standard DS (no IQ) the computer has nothing to do with the speed of the cart. Is anyone able to shed any light on these claims or maybe any ideas with next steps?? Thanks!

[forr33l]

Incase anyone else runs into this problem. It was fixed by a new controller. After disassembling the old one I noticed that some of the capacitors were not working.

[Fairtax4me]

Was getting ready to suggest that maybe the brushes in the motor were bad.

Glad you found the problem!

Also to answer your question about the function of the controller. Yes, it does control the speed of the motor. The negative from the motor has to flow through the controller before it’s able to go back to ground.