When installing a 12 volt accessory
(lights or radio) on 36 volt or 48 volt
cart you will want to install a voltage
convert/reducer. 
 
The accessory will pull from all 6 batteries
rather than just two. 
 
If you are only installing one 10 Amp Accessory you can use RH-VOLT-0003 10 Amp
Reducer/Converter
 
If you want to install both lights
(approx 10 Amps) and a radio (approx 10 amps)
then you'll want the 25 Amp Reduce/Converter Item RH-VOLT-0002.