[villagetinker]

UPDATE.
I worked on the cart today, and there was a wiring error causing all of the problems. Once we figured our what was going on we got the radio to work. Aslo, the wiring problem caused the fuse to blow.

As for the basic "12 VDC" connection on the electric carts. WOW did I get an education when I did some serious research on Google last night. It appears that most (if not all) Golf cart manufacturers simply tap the 36 or 48 VDC battery string to get something close to 12 VDC for lights and accessories.

While this does work, it has some disadvantages.
1. The 2 batteries that are tapped for the 12 VDC supply are getting additional load that the other batteries in the string never see.
2. If you drive a lot a night, or use a lot of 12 VDC accessories, this additional load could shorten the life OF THE 2 BATTERIES used to supply the 12 VDC.
3. Because the batteries are NOT being discharged EQUALLY it is probable that they will not be recharged equally.
4. These 2 batteries will also require additional maintenance (water), etc.
5. It is conceivable that these 2 batteries will have a shorted life then the other batteries.

I learned early on in my electrical engineering career that it was very bad design to tap a battery string for lower voltage loads, and utilities go to great lengths to avoid doing this.

I also found that DC - DC converters for 36 (or 48) VDC to 12 VDC tend to be expensive, especially if these are going to supply all of the DC loads, lights, turn signals , horn, radio, etc. However, using a converter spreads the load across all of the batteries and completely eliminates the uneven loading of a tapped string.

Now, I have no idea if I have just made a mountain out of a mole hill, but I thought that I would provide this information for all users of electric golf carts, just in case you are seeing some of the above problems.

Hope this helps.