08 cc precedent possible speed sensor problem?

Hello. New golf cart owner here. Bought a 08 club car precedent a couple weeks ago. It seems in very good shape....very clean. It has 4-12 volt batteries that are 2 years 4 months old. Haven't ridden cart much until this weekend. I have, during these 2 weeks, removed & cleaned all battery cables & checked water in batteries.

Noticed yesterday that it would get up to speed....then slow down to about 8 mph...then surge back to 14mph.......back & forth. Then, a little later. .....it would only get up to 8mph......never going full speed. Charged batteries last night. This morning, got up to full speed. ....& stayed there for a while. Then.....started speeding up/slowing down again.

Saw the speed sensor sticky.....& performed the test where you push the cart while key is on &switch in forward or reverse. It failed that test..... it didn't beep or apply brake. I feel pretty confident the speed sensor is bad but wanted to get yalls opinions.

Can a speed sensor be an intermittent problem? Also....the reverse buzzer sometimes works & sometimes does not. I didn't think speed sensor would have anything to do w/ reverse buzzer. ....so got me thinking I might have a controller problem?

Thanks for any help!