Well this is weird... V. accessory fuse

[LJRuddy]

So I decided to finally make my sub/amp install look pretty today and one of the things I did was replace the signal wire that was shoved into the 20amp accessory fuse plug with a Tap-a-Fuse block. Crimped my XM radio wire and amp signal wire into the fuse and reinstalled. Instantly, the sub gave me a shit ton of feedback. For some reason, the amp is now getting power all the time with this tap-a-fuse installed. What happened? Does the accessory fuse always get power even with the key 'off'? If so, why did my sub/amp only turn on with the key on when the wire was just pushed into the fuse slot?

If you dont know what a tap-a-fuse is: http://www.autozone.com/autozone/ac...-25gq?itemIdentifier=32416&_requestid=1286581

 

[SHOMON]

I think he is using the circuit for amp remote turn on.

 

[93rev2sev]

Yeah. you'll have to explain your wiring in a bit more detail. but here's what I edited


You shouldn't be anywhere near the factory fuse block in order to install any audio equipment, whatsoever.

All wires for any accessory that draws more power than the unit it's replacing should be run straight from the battery and fused within about 18" with the appropriate fuse for the accessory in question

Any attempt to make a 20 year old circuit bear more than it was designed to do 25 years ago is akin to asking for a car-b-que.

Having said that...What "signal wire" are you talking about? There's usually red, black, and blue (remote SIGNAL wire).


If you want, run one large power wire into the trunk and fuse it at the battery. From there, you can branch it into multiple power leads with an aftermarket fuse block.

I don't think that's the fuse block you mean, so I'll have to assume you want to use the car's accessory power circuit as a remote power turn on signal wire, such that when you turn the key to "on" or "accessory", the amp turns on...

Going by that, I still don't know why anyone would do that. All after market head units and even the stock ones have a remote turn on wire built in. It's the blue one.

 

[LJRuddy]

You shouldn't be anywhere near the factory fuse block in order to install any audio equipment, whatsoever.

In the interest of keeping things simple and neat, I chose to run my 12v signal wire (from the amp) to the fuse block in lieu of cutting/splicing wires in the trunk.

All wires for any accessory that draws more power than the unit it's replacing should be run straight from the battery and fused within about 18" with the appropriate fuse for the accessory in question

Any attempt to make a 20 year old circuit bear more than it was designed to do 25 years ago is akin to asking for a car-b-que.

The signal wire does not draw any current but maybe 100mA if that. The main power wire from my amp was run straight to the battery via 2 gauge wire with a 20amp inline fuse attached to it. I put a small fuse in it so that the fuse will blow before I over drive the sub or melt wires.

Having said that...What "signal wire" are you talking about? There's usually red, black, and blue (remote SIGNAL wire).

Im talking about the 12v signal that needs to be hooked to the amp. I used yellow wire but it really doesnt matter as im not letting code enforcement inspect my wire job.

Going by that, I still don't know why anyone would do that. All after market head units and even the stock ones have a remote turn on wire built in. It's the blue one.

Yes this one has that. But, like all wires, they need to be connected to a power source. Thus, I chose the fuse box under the dash.

Im not sure why we're talking about how to set up a sub and amp. I've had this set up in my car for over 2 months now without an issue. My only question was why all of a sudden to I get constant power at the accessory fuse when prior to the installation of a tap a fuse I was only getting power there with the key on.

 

[93rev2sev]

When you do crazy shit, crazy shit starts happening? Just take the half hour needed to run a remote wire to the radio. ****...you said it...18ga speaker wire will do the job.

 

[LJRuddy]

When you do crazy shit, crazy shit starts happening? Just take the half hour needed to run a remote wire to the radio. ****...you said it...18ga speaker wire will do the job.

How is installing a tap a fuse crazy shit? I didnt even cut a single factory wire in this entire install and yet its crazy shit? Tell me, sir... How else would you have ran a wire with zero current draw?

 

[frankanthony]

What fuse number are you using? Do you have a Digital Multi Meter or volt meter? If so disconnect the remote wire and test the wire from the tap-a-fuse. I have seen in the past where an amplifier has a small transistor failure and leaks voltage through the remote wire and back feeds the circuit.

This is how state changes work...

Constant = Key in any position, will always be HOT unless circuit is open.

Accessory = Will be HOT when key is in IGNITION position and in ACCESSORY position. Will be OFF in START and when key is in OFF position.

Ignition = Will be HOT when key is in IGNITION position and START position. Will be OFF when key is in ACCESSORY position and OFF position.

Start = Will only be HOT when key is in START position.

 

[WSC-SHO]

Carefull with them tap-a-fuses, CRAZY SHIT right there...