# Ford factory amp turn-on pop - tried resistor...



## JBThompson (Oct 3, 2013)

Threw a head unit in my 05 Explorer and knowing the factory sub amp takes a 5v input I used a 1.5K Ohm/.5W resistor on the remote lead. Still pops, but not consistently. I thought maybe I got the resistor too hot when I soldered the leads but I tried two others and the result is the same. Would stepping up to a bigger resistor be the thing to do, or would that drop the voltage too much?


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## cobb2819 (Jan 13, 2011)

JBThompson said:


> Threw a head unit in my 05 Explorer and knowing the factory sub amp takes a 5v input I used a 1.5K Ohm/.5W resistor on the remote lead. Still pops, but not consistently. I thought maybe I got the resistor too hot when I soldered the leads but I tried two others and the result is the same. Would stepping up to a bigger resistor be the thing to do, or would that drop the voltage too much?


4.7K Ohm is what we typically used on Mustangs, IIRC.


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## JBThompson (Oct 3, 2013)

That's interesting. Everywhere I've read online they say to use 1.5K so that's what I used. Actually that's a lie. I found a video online on making a stepper using two 1K/.25W resistors, and that actually wouldn't let the amp turn on at all, hence the 1.5K. I'll pick up a 4.7K and see how that goes. Thanks!


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## kustomkaraudio (Jun 20, 2009)

These work pretty good. 


AFDI-5V [AFDI-5V] Axxess Integrate, Comprehensive Interface Products


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## Sine Swept (Sep 3, 2010)

I tried a resistor and a 5 volt regulator on a 2007 Mustang, neither solved the turn on pop for me.


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## JBThompson (Oct 3, 2013)

The good news is this is only a temporary issue. Soon as I find a suitable driver to replace the stock 8" the factory amp will go on a shelf in the garage.


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## What? (Jun 5, 2008)

This will work much better. Use at own risk.


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## grumblin (Oct 23, 2015)

What? said:


> This will work much better. Use at own risk.


Correct - a voltage divider is the only way ...


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## JBThompson (Oct 3, 2013)

The divider was what I tried first but with two 1KOhm/.25W resistors and the amp didn't power up at all.


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## What? (Jun 5, 2008)

I always end up with two different value resistors and you can measure them with a meter to see what the output is. I would put 13.5ish volts in and measure the output. If the output is 5-6V, you should be good.

Or, you could use the Metra AFDI-5V 
http://www.metraonline.com/files/products/INSTAFDI-5V.pdf


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## Billy Jones Dio (Nov 1, 2015)

You need to be careful with where you mount the resistor. Resistors in general are supposed to get hot, and their rating + material it's built from dictates how much heat they can dissipate, but that's often when they are mounted 1/2" above a printed circuit board. If you just wrap electrical tape around and hope for the best, it could actually burn up if not designed to handle the power being sent through it to melting whatever it touches.


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## grumblin (Oct 23, 2015)

Billy Jones Dio said:


> You need to be careful with where you mount the resistor. Resistors in general are supposed to get hot, and their rating + material it's built from dictates how much heat they can dissipate, but that's often when they are mounted 1/2" above a printed circuit board. If you just wrap electrical tape around and hope for the best, it could actually burn up if not designed to handle the power being sent through it to melting whatever it touches.


This.


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