How does an aftermarket stereo amp help fuel pump rewire

[calico]

Hi all,

While using the search function for fuel pump rewire, i came across a thread where someone stated if you have an aftermarket stereo amplifier, it shortens the time to do the fuel pump rewire to 5 minutes or less. Does anyone know if this is true and if so does anyone have instructions to accomplish this.

thanks

 

[dave99gst]

just because if the amp is in the trunk, then you allready have a large power wire ran from the battery to the rear.
Its just 1 less step.

 

[calico]

just because if the amp is in the trunk, then you allready have a large power wire ran from the battery to the rear.
Its just 1 less step.

Thanks...so what step on the vfaq should i start on since i have an aftermarket amp in the trunk?

 

[steve]

It shortens the process since the most time consuming part is running the power feed wire to the battery. You still follow all the VFAQ steps except you run the power wire to the feed for the amp.

 

[calico]

thanks for all the replies....

 

[krummel21]

I was going to y my amp power wire one to fuel pump and one to stereo amp. My question is does this cause the ampridge to cut in half? Or is something effected negetively by doing this?

 

[Atuca]

I ran two seperate wires because I thought the point was that it has power untouched by anything else on a thicker gauge wire. Anytime you sub hits hard doesn't that draw power on that line pretty heavily? I guess it wouldn't matter in the end since it pulls from the same battery, but just the way I did it was fuse them seperately and ran two wires.

To each his own

 

[DougR]

Install a 1 Fared Cap or larger. Depending on how mutch amperage you draw with that amp. Your power drain when your subs hit will go away..
A basic Cap will do. Dont waste money on the fancy ones with a digi volt meter installed on it.

 

[dsmmikej]

If you have a small gauge power wire from the battery to trunk, say like a 14gauge on a 500watt amp, you might want to consider getting a bigger gauge wire if you plan on doing the rewire. The reason being that if you have a too much current being drawn away from the battery by the amp, your voltage will drop closer to the amplifer. In otherwords get a multimeter and a buddy, while listening to your music at the highest level you like to listen to, go drive and get you buddy to test the voltage by the amplifier throughout your rpm range. If you notice a drop below 13.6V you might want to run a bigger gauge power wire to do the fuel pump rewire. If you are running a bigger amp running more than 400watts you should have a power cap also, I don't think those mits alternator like high current draw as most alternators don't.

 

[UGOT8UP]

Install a 1 Fared Cap or larger. Depending on how mutch amperage you draw with that amp. Your power drain when your subs hit will go away..
A basic Cap will do. Dont waste money on the fancy ones with a digi volt meter installed on it.

Don't add a farad, they only hurt your system output, lighting quick dischard---long charge time, and it add's another thing for the alt to charge. farad's are for show car's!

 

[dsmmikej]

good rule of thumb for what size cap to run is 500watt is good for .5farad, 1000watts for 1 farad, 2000watts for 2 farad, and so on.

 

[UGOT8UP]

Use the money spent on a farad to buy a HO alt, if you still need more power get another battery. Farad's are a wast of money and should not be used as a band-aid for your charging system!!!

using a capcitor does help.......... - Car Audio Forum - CarAudio.com

 

[krummel21]

I think I have 10 gauge or higher running back there not sure since I ran it so long ago. I just have a 500 watt legacy amp hooked up to it. Which means it probly is only grabbing 400 watts at max. I will try and do that check with the meter not sure how safe it will be though. haha. I just bought a new battery wonder if I could just return it what battery would be best?

Edit: Just looked at yellow tops and those things are around 200 dollars. Not interested in spending that much. Knowing the amp size do you think I will be alright with the way I was going to do it?

 

[rstchris]

I have a 4awg going to a 270w amp so i soldered my fuel pump wire to the side of it and used the stock + to switch the relay and used the stock ground as well as a new one. Works great for me.

 

[UGOT8UP]

I think I have 10 gauge or higher running back there not sure since I ran it so long ago. I just have a 500 watt legacy amp hooked up to it. Which means it probly is only grabbing 400 watts at max. I will try and do that check with the meter not sure how safe it will be though. haha. I just bought a new battery wonder if I could just return it what battery would be best?

Edit: Just looked at yellow tops and those things are around 200 dollars. Not interested in spending that much. Knowing the amp size do you think I will be alright with the way I was going to do it?

I would not run the amp and the fuel pump off of a single 10ga wire..use the 10ga wire for the fuel pump and run another for your audio system.

You can get a yellow top for cheaper than that. My Honda yellow top was $180 and my standard one was less than $140. The Honda yellow top is smaller and lighter than the BIG ones and it is PLENTY strong enough for a small system or a high demand race car.

 

[krummel21]

Alright thanks, do I need to have an empty tank to do the install? Also is it necessary to use flare wrenches per vfaq? I don't have any and don't really want to buy them if a people have gotten by with regular wrenches.

 

[SeaveeDSM]

Alright thanks, do I need to have an empty tank to do the install? Also is it necessary to use flare wrenches per vfaq? I don't have any and don't really want to buy them if a people have gotten by with regular wrenches.

As others have said do not try to double up an amp and fuel pump on one + wire (I guess unless its like 4 gauge). I also second the high output alternator recommendation, especially if you are making a fair amount of power AND have a strong stereo system with amp involved. I posted a "review" on an HO alternator recently here: http://www.dsmtuners.com/forums/newbie-forum/323547-alterstart-high-output-150a-alternator-2g-review.html


Don't know about the absolute need for flare wrenches on the FP install/rewire - sorry.

 

[UGOT8UP]

Flare wrench

You don't really need to do an HO alt, first thing to do is the big three, doing this will make your charging system run to it's peak performance.

Use 4ga wire for all of this on a stock upgrade--Big system's with bigger HO alt, and multiple batteries need bigger wire.

1. Ground your engine block to your chassis.

2. Ground the neg post of your battery to your chassis.

3. Run a hot wire from the charge post of the alt to the pos terminal of your battery.

If your light's are still dimming after doing this, it is now time to do a HO alt swap than add another battery if needed.

 

[Rob10_99]

8up hit it, even someone with 10farad cap will suck if they don't have decent grounds.

 

[krummel21]

Sorry this is probly a newb question but what do you mean by ground the block? What wire are you talking about? Grounding the battery do I just run a wire from the chassis to the neg terrminal and not cut any wires just add this? Same with the alt. do I cut the factory charge wire?

 

[UGOT8UP]

engine block...do not cut any wires, your just adding atleast 4ga wire inbetween the alt and the batt...Make sure that you have a good clean connection, IE make sure you grind or scrape all the paint off of the chassis and engine block before making your connection's