36V Nightmare... Need Help Please!

[arkmaker]

Hello everyone. I am a total newbie to carts other than driving them when I was younger and played golf! I picked this cart up ('93 36V) last week so my wife could get around the property. Everything seemed fine and then she said the charger was not shutting off. The guy I got it from had taken out the 2 center batteries and put in a 12V. Told me it was acceptable as it still made up the 36 total volts. Made sense to me at the time, but now I am not so sure?? Batteries are pretty much dead and cart will not run. This is a Rohs charger which I don;t think is the original. Anyway, I got to looking closer at the batteries and found that there were a couple of wires not connected. So there is a red/white wire from the fuse not connected as well as an orange one. Just hanging loose. There is an idiot light on the dash to tell if the batteries are getting low. I popped out the panel and found that both of those wires are disconnected as well. You can get the picture....a nightmare! So, I guess my questions are; is it ok to run that 12 volt battery in the middle of 4 6 volt batteries? And what are my hanging wires (red/white and orange)? The idiot light would be nice to have working as well, but I had planned on adding a gage anyway. I am trying to figure out how to add a picture, so you can see my mess first hand. Thanks, Rich