Originally Posted by cverneau
I've got a question regarding the add-a-fuse and apologize if this is long winded as I have fairly limited electrical knowledge.....
Slot #2 (or "b") is the fuse for the accessory, and slot #1 (or "a") is the original size fuse for the original slot. Instructions for the add-a-fuse tell you to put the fuse you require (in my case - 2A) in slot #2 and plug it into the fuse panel to make sure it works - IF IT DOES'NT, YOU NEED TO ROTATE THE ADD-A-FUSE. This is telling me that there is a diode or something which is allowing current to flow only one way.
Here's my question - With a fuse in slot #2 ONLY, the add-fuse must be installed correctly for it to work.
With a fuse in both slots #1 & #2, there is juice to both slots no matter which way the AAF is installed.
How is this possible and why does having a fuse in slot #1 allow juice to flow to slot #2??
If it's plugged in INCORRECTLY and the fuse in slot #1 burns, there will suddenly be no power to the fuse in slot #2.
If it's plugged in CORRECTLY and fuse #1 burns, then fuse #2 will still have juice.
I guess the question is this: What kind of problems or damage would result by plugging the AAF in incorrectly if anything??
I believe the way the Add-a-fuse works is this:
You have a power input side, power goes to the supply side of slot 1 and the supply side of slot 2. From there, power goes across slot one and back to the fuse panel to power whatever it's intended to power. In slot 2, power goes across the fuse and out to your new accessory. This means there is a solid connection between the 2 supply sides of both slots and there is a broken connection between the output sides (one goes back to the fuse panel, one goes to your accessory). When you install the AAF backwards, power must travel across the slot one fuse, then it splits, part of the power going to the fuse panel to power whatever it's supposed to, the other part going through slot 2 and to whatever you added. This means the slot 1 fuse is acting as the fuse for both circuits which means if slot 1 burns out, slot 2 will no longer get power.
If you plug the AAF in incorrectly, that just means the slot 1 fuse is carrying the load for both circuits. Worst case, you blow out the slot 1 fuse.