[JMEZARIC3]

looking for ideas to hard wire a waterproof Bluetooth speaker to a 2016 Yamaha cart. Any ideas?

[villagetinker]

OK, I am confused, Bluetooth is a wireless technology, if you are trying to connect a power supply for the speaker this is a different story. Is the Bluetooth speaker equipped with a port to plug in an external power supply, or is it just battery operation? If you have a port to plug in a power supply, you will need a suitable converter for the carts battery voltage to that required by the speaker. You will need correct polarity to the power converter and to the speaker and you will need the correct plug. If the speaker is battery operation, then it would need to be modified, and all of the previous equipment would be needed.
Try contacting the manufacturer of the speaker and see if they offer an adapter. If not send me a PM I can probably help you, but be warned you will probably spend $20 or more just for the DC converter.
VT

[retiredguy123]

I am not very familiar with golf carts, but if they have an outlet similar to the cigarette lighter in cars, and the bluetooth speaker has a USB cable for power, then you can buy a simple plug-in adapter to convert the cigarette outlet to a USB connection.

[villagetinker]

RetiredGuy, good point, the OP did not specify gas or electric, Also, if electric, the cigarette lighter may or may not work, I have seen some very strange wiring to these, one battry connected (8 volts), 2 batteries connected (12 volts or 16 volts), vehicle supplied 12 vdc stepdown (around 12 volts). If it is gas, then there is a standard 12 volt car battery and your solution is a very good one.

[permanentvacation]

It sounds like you might be looking for a water-proof sound bar for your golf cart. These are permanently mounted to the golf cart and hard wired to the carts power supply. See the attached article for some suggestions.

The Best 5 Golf Cart Soundbar To Buy In 2018 - bestwaterproofspeaker.com

[Kahuna32162]

The soundbars in this article look very nice, I'm just not sure I would want to pour out over $700 bucks just to listen in my golf cart. I have a cube shaped BT speaker that sits in one of the holders on my dash. Plugged into the usb port for power and connects to my phone for music. Total cost $35. Cart is a 2018 Yamaha from Carts and Clubs.

[tophcfa]

We have a UE Boom water resistant blue tooth speaker that fits in a cup holder. I mounted a cup holder on one of the rear roof support bars is a dry place that is not noticeable unless one is really looking for it. That way I don't worry about it getting stolen when we park in public places and it also keeps our other cup holders open. It is not hard wired, but it is not necessary. We bring it in the house every couple of weeks and plug it in for a quick charge. The battery has never run out on us. The sound quality is great and it plays way louder than we would ever need it to. And where we have it mounted allows us to hear it well with the volume lower so that we do not disturb other people. Hope this helps.