Interior fuse box power tap?

#2
I don't think any of them are. I tried to find one for a switch that I added and noticed that the factory items use negative switching. So both sides of all fuses (unless blown) are hot. That's with the car off.
But if you find out anything let me know!
 
#3
You can use a voltmeter to measure if the fuse is always hot, or switched on with the ign key.

Use an "add a circuit" accessory which plugs into the fuse box and retains the orig fuse, plus it also gives a spot for the add on circuit fuse. It's a tidy and wire harness safe method of adding toys to your ride. I'll try to post a pic soon of what mine looks like.
 
#6
image.jpeg As promised. Notice I added a circuit to my acc outlet which is fused, so there are 2 fuses upper right....hard to see. I also added another circuit to a vacant fuse slot so there is only 1 fuse shown bottom row. This slot is switched on and only powers up with the ign key. You will not be able to retain using the fuse box cover, but minor issue IMO.
 
#7
View attachment 1807 As promised. Notice I added a circuit to my acc outlet which is fused, so there are 2 fuses upper right....hard to see. I also added another circuit to a vacant fuse slot so there is only 1 fuse shown bottom row. This slot is switched on and only powers up with the ign key. You will not be able to retain using the fuse box cover, but minor issue IMO.
Correction above.....the bottom row add a circuit is always on, not switched. My bad.
 
#8
I don't think any of them are. I tried to find one for a switch that I added and noticed that the factory items use negative switching. So both sides of all fuses (unless blown) are hot. That's with the car off.
But if you find out anything let me know!
How were you measuring that? Not all fuses have power at all times and definitely not from both sides. Power only travels one direction through a fuse.
 
#12
I used a fluke meter with the car off, keys removed. Couldn't find anything that wasn't already "hot".
Negative switching is common in most cars. I think that's why everyone says to remove the negative from the battery when working on them.
 
#14
There is a certain science to a fuse box. I've wired up a lot of projects over the years to cars, bikes, even a couple of boats. Fuses are the most important element in a circuit aside from the function of the circuit. Fuses must be properly rated to protect the wiring harness and the designated load such as a stereo amplifier or fog lights etc.

If you have a Fluke DVM then I will assume you know how to use it and you should be able to find the slot(s)
that is switched. For example, I used the switched power outlet fuse slot to add my circuit. The power outlet is
fused at 15A. I was adding a 5A fused circuit, so I dropped the outlet fuse down to 10A as it was primarily used for a low current draw phone charger. 10+5 = 15 so I preserved the 15A rating of the fuse slot. Very important not to overload the 'slot'.

One reason for disconnecting the negative cable from the battery is that modern cars utilize negative grounding
with the metal chassis of the car being used as a giant piece of wire. If are you working on an energized circuit
and inadvertently slip with a meter probe or bare wire and touch the metal body or chassis, you can damage stuff because there is a complete circuit allowing current flow. Fuses can blow and it's a hassle to locate them and replace. Easier to just pull the neg cable first.
 
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