How to make an old Golf Cart work again.
Step 1: Get rid of old batteries
Ususally golf carts have 6 - 6 Volt batteries in them, If they are still good you can keep them, but if there not you will have to get rid of them.
Step 2: (If old ones are bad) find some new batteries
The batteries in my golf cart were completely dead. I looked around online and at local stores for the cheapest new batteries I could find. I was going to replace all 6 of the golf cart batteries but, I decided to use 2 - 12 volt deep cycle rv batteries instead (much cheaper, ~$150 for 2 - 12 volts instead of ~$450 for 6 - 6 volts) The 6 - 6 Volts would give it 36v 220ah and the 2 - 12 volts would give it 24v 120ah. using 12 volts will give you half of the runtime and about 2/3 the speed of the 6's but its much cheaper.
Step 3: Rust
The motor in my cart was pretty much fine, only a little rust. I used WD40 on most of the moving parts. I still have to get some good grease for it though.
Step 4: Speed Control
The speed control in my cart is really really old, it only has 3 speeds and if your going slow all the extra power is wasted in heat. I could get a new one for around $200-$400 which would make it much more efficient and much smoother.
Step 5: Stuff I plan on adding later
Battery Voltage/Capacity meter
Plastic/Plexiglass Side to keep rain and wind out