Using an Add a Circuit

Hey guys, I am going to attempt to do the USB mod here.

http://www.tacomaworld.com/forum/2nd-gen-tacomas/47366-my-usb-port-write-up.html

I like that I only need to take apart like two panels.

Anyways I am going to go to autozone and purchase an Add a circuit. I don't know how these things work. Do I need a certain one that is a certain voltage or what? I also have a prerunner. Does it matter what slot I put it in on the panel? What do all these numbers mean on the different colored plastic things? Should I put it in an empty slot or what? lol I know im a dumbass



Am I going to have to buy a 20A Fuse as well?

Sorry for all the questions. I understand everything except for the wiring stuff. Any help would be greatly appreciated.

Thanks

 

There are only 2 kinds of add a circuit. One for small fuses and one for the older style big fuses. You need the smaller one. Those colored things that you are referring to are fuses. The numbers indicate how many amps they are rated at. Yes, you will need the appropriate size fuse for whatever you are trying to feed power to. To figure out which one to replace with the add a circuit, you need to determine which ones have power on them with the switch if you want the component you are adding to be switched. Find a fuse that would only have power when the switch is on using your owners manual. The radio would be a good one that is switched.

 

Thanks for the explanation. I am going to take a typical cigarette lighter to USB converter and disassemble it. And then plug it into the wire that hooks up to the Add a circuit. What size fuse would I need for this?

 

The "add a circuit" adapters are cheap enough that you should buy a few in each size while you are at the parts store...... they are always great to have on hand.

In my 08, I actually used one of each size for my mods depending on which fuse block I tapped into.

 

Does your USB converter specify how much maximum current it uses?

If it doesn't, I'd look at the power wire size and use a fuse that is at or less than the maximum current rating for the wire size. (The power wire inside the adapter is probably the smallest part of the power circuit; always go by the smallest wire gauge in the circuit.)

USB 2.0 ports allow a maximum current draw of a half amp per outlet, which means about 2.5 watts. At 12 volts, 2.5 watts draws less than a quarter amp. Assuming some overhead for the electronics inside the USB adapter, I would figure a 3 amp fuse would be completely adequate.

I would still check the power wire size inside the adapter to make sure 3 amps wasn't too much for the wire.