Fuse Tap For Adding Electric Circuit Power

[MrAl]

I actually bought these from Autozone (in store), and yes 10 Amp max is also what the manufacturer says. I can double check, but if remember right, mine are made by Buss.

I thought i replied to this already but here is a condensed version.

First, maybe you want to post a pic or two.

Second, i was saying that we might have to be careful with these taps because if we position the wire so that it comes off the fused side then in order to draw say 10 amsp on a circuit that was already 10 amps then we'd have to change the fuse to 20 amps, but then the original 10 amp circuit is no longer protected as well.
So if we position the tap such that it takes off the direct 12v line side (no fuse yet) we would have to place an inline fuse in the wire to protect the new circuit. Then we have to hope that the original feed wire to the 10 amp origional fuse can handle 20 amps.
A slight risk is that if the new line shorts to the body before the inline fuse, that would probably blow a main fuse.
Just some stuff to think about when doling this kind of mod.

Let's see if this reply goes through ok, maybe i hit the wrong button.

[LATER] OK i checked it got posted this time.

[BEJinFbk]

Or just use the accessory connector.

[MrAl]

Or just use the accessory connector.

Hi,

Yeah i was going to use that at one time and never got around to it but now i forgot where it was located.

[rrres]

This is what it looks like, fuse #4 works well for this.

DSC_0058.jpg

Do you have a picture or description of how you routed the wires to the under-dash? I'm about to add these add-a-circuits. What I was thinking is to have the wires, somehow, go into the engine bay, then through the factory conduit next to the ABS module, and into the dash...but that seems like the long way. You mentioned that you were able to go from the fuse box into the dash directly.

[abscate]

Then we have to hope that the original feed wire to the 10 amp origional fuse can handle 20 amps.

You always have to worry about this. The taps split the load so that the two outputs are independently fused downstream.

If it’s just phone charging you are doing, it’s only a 1-2 amp draw at most, the upstream wire will be fine

If its an oxygen generator, its best to wire right off the battery, with a fuse of course.

[Sveedy]

I'd like to get a in-line fuse adapter that will attach to the battery, and handle a 25amp fuse w/ 12 gauge wire. But with auto electric being a weak spot with me, I'm not sure what to get. I've found one on-line, but it says 32v. I'm wondering if that is the max, so then I could use it with the 12v system. Times like this make me miss Radio Shack.

[abscate]

Maximum voltage rating, correct. You can safely use that with a 12 V system

[rrres]

...There is even an opening under the fuse box where the cable can be routed thru to the underside of the dash...
Dirk

Thanks for this lead! I did some looking around and found the hole you were talking about. woohoo! Looks like I'll be playing with wires today.

Fuse box to dash access

20220424_095949.jpg (363.43 KiB) Viewed 648 times

[abscate]

Check math above

16AWG has resistance 4.016 Ohms per 1000 feet.
For 1 foot that means a resistance of very close to 0.004 Ohms.
At 10 amps, that drops 0.04 volts.
0.04 volts is close to 0.003333333 percent of 12 volts.

0.04Volt /12 volt is about 0.3% loss, too small to measure accurately

Link to the accessory connector thread 24/35 , there are more links in the suggested thread library too.

viewtopic.php?t=69527&hilit=Accessory+connector

[MrAl]

Check math above

16AWG has resistance 4.016 Ohms per 1000 feet.
For 1 foot that means a resistance of very close to 0.004 Ohms.
At 10 amps, that drops 0.04 volts.
0.04 volts is close to 0.003333333 percent of 12 volts.

0.04Volt /12 volt is about 0.3% loss, too small to measure accurately

Link to the accessory connector thread 24/35 , there are more links in the suggested thread library too.

viewtopic.php?t=69527&hilit=Accessory+connector

Hi,

Not sure what you are getting at here.
As you probably already know, when we cant measure something directly sometimes we can turn to statistical methods. This one is super simple.

Measure the resistance of 1000 feet of AWG 16 and divide by 1000. That gives the average value over the length of wire.


Sometimes you can pump a large current through something to check the resistance. You may have to measure the temperature too though. The larger the current amplitude, the higher the voltage drop.

For my application i am using 15 feet of AWG 16 but it goes both ways as it is two wires. So in total i have 30 feet. That is somewhat significant at 10 amps but it should be ok for now. I think i can shorten it quite a bit too once i find the firewall wormhole.
Do firewall wormholes really exist? I'll find out soon
Maybe you can stick a wire though yours in the engine compartment and it will come out mine in the interior of the car, that way i'll find it faster