# Add relay to prevent amp from drawing power when car is off... Question



## KillerQ (Nov 2, 2012)

Hey all,

Even though I have my amp wired to turn on with aux power, it's still drawing minimal power as my car will die if sitting for a week or so.

I was told that I could add a relay to cut physical power connection to the amp when the car is off - I searched and found an existing thread on this forum - so, does THIS seem like the right post/thread that I should follow?

Thanks in advance, 

Matt!


----------



## wooferdog (Mar 31, 2011)

That is for low amperage only like for the remote turn on wire. You would need a relay capable of high amperage to install on your main power wire or a valet breaker that you could manually turn off when not in use.


----------



## jcpahman77 (Mar 5, 2013)

Rated for 350 amps continuous and 500 amps surge power. Click the pic for more info.


----------



## nosaj122081 (Apr 7, 2012)

What makes you think your amp is drawing any power when off, have you verified that with an ammeter? If the voltage to the remote turn on is off, the amp shouldn't draw any current, not even a little. IMO, you need to look elsewhere in the car for your current draw.


----------



## Spyke (Apr 20, 2012)

nosaj122081 said:


> What makes you think your amp is drawing any power when off, have you verified that with an ammeter? If the voltage to the remote turn on is off, the amp shouldn't draw any current, not even a little. IMO, you need to look elsewhere in the car for your current draw.


+1^^^


----------



## ATOMICTECH62 (Jan 24, 2009)

nosaj122081 said:


> What makes you think your amp is drawing any power when off, have you verified that with an ammeter? If the voltage to the remote turn on is off, the amp shouldn't draw any current, not even a little. IMO, you need to look elsewhere in the car for your current draw.


x2.I have never seen an amp pull even small amounts of current when off.
However,large stiffening capacitors will drain a battery after a few months.


----------



## RNBRAD (Oct 30, 2012)

ATOMICTECH62 said:


> x2.I have never seen an amp pull even small amounts of current when off.
> However,large stiffening capacitors will drain a battery after a few months.


Actually a few weeks and with a smaller or compromised/weak battery, just a few days or less. Good call though.


----------



## 07azhhr (Dec 28, 2011)

Agreed with the others that the amp should not be the cause of this.


----------



## Spyke (Apr 20, 2012)

Or disconnect the amp and see if your battery still dies after a couple days. How old is the battery? Batteries in poor condition can lose there charge on their own without even being connected.


----------



## Shadowmarx (Feb 12, 2012)

The only way I know is if the caps are bad...
But think that was stated above...


----------



## D-Bass (Apr 27, 2012)

99.99% chance it's not the amps. Phantom draw on an amplifier is going to be very significantly less than the battery's own internal resistance draw.
What's the year, make, model of the vehicle?


----------



## KillerQ (Nov 2, 2012)

Hey all,

Thanks for the responses. I went to a car place and had the charging system/battery/alternator tested - all was fine. The battery is a little over a year old (2006 Ford Escape).

The car ONLY started dying after sitting for a week after adding the amp - so that's the only variable that popped into my mind. It's the only component wired directly to the battery (well, the capacitor is as well).

Some guy at the car place mentioned that "I do car audio installs all the time, and I often see the amp killing batteries when the car is off. I always add a simple relay to prevent this and it solves the problem." So, that's where that idea was planted in my head.

Today, I will pull the fuse on the power line that feeds the amp and cap. I'll see how that impacts the battery as well as do some more testing if that doesn't solve it....

Thanks in advance, 

Mat!!


----------

