4 replies to this topic

[GermanMoreno]

Hello there! I have this annoying issue. I installed an aftermarket stereo + an amplifier.

 

- Sometimes, not always, the radio shuts down when: I turn on the spots, press the horn, or when I switch the wipers off.

- When I turn off the car, I can hear that the speakers shut down a couple of seconds after the engine has stopped, even if the ignition switch is completely closed. I assume this is the amplifier.

 

Could it be a ground, bad amplifier, or a wrong live feed to the stereo or amplifier? voltage drop? any other ideas? What should i do?
I would like to know where to start before thinking battery / alternator

 

 

My car is a Jap Spec Cooper 91.

 

Thanks!

[Spider]

Many of these modern Radios have 2 supplies to them, one that live all the time, to keep the radio stations in memory and keep the clock running, while the other supply is from the key to bring the music box alive.

 

Most I've found actually run from the Live feed and the key circuit essentially activates a relay or an electronic equivalent inside them, which senses voltage level rather than voltage presents to do the switching.

 

When you honk the Horn, hit the spots etc it causes a momentary dip in the voltage that causes these 'smart' circuits to think the car's being shut off, but the voltage quickly rises again to a level where it will be on, but as they are 'smart' circuits, they have a small mini computer that takes time to shut down and time to boot up again,,,,

 

Most of the time, I've just added a 3 amp diode to the circuit that comes from the key and then added a big capacitor, around 2000 or 4000 microfarad to the radio side of the diode. This usually stores enough power to keep the music box alive over these dips in power and the diode stops them trying to keep the whole car alive from the capacitors. These type of capacitors are usually polarised, so just watch that if you do this.

[GermanMoreno]

Many of these modern Radios have 2 supplies to them, one that live all the time, to keep the radio stations in memory and keep the clock running, while the other supply is from the key to bring the music box alive.

 

Most I've found actually run from the Live feed and the key circuit essentially activates a relay or an electronic equivalent inside them, which senses voltage level rather than voltage presents to do the switching.

 

When you honk the Horn, hit the spots etc it causes a momentary dip in the voltage that causes these 'smart' circuits to think the car's being shut off, but the voltage quickly rises again to a level where it will be on, but as they are 'smart' circuits, they have a small mini computer that takes time to shut down and time to boot up again,,,,

 

Most of the time, I've just added a 3 amp diode to the circuit that comes from the key and then added a big capacitor, around 2000 or 4000 microfarad to the radio side of the diode. This usually stores enough power to keep the music box alive over these dips in power and the diode stops them trying to keep the whole car alive from the capacitors. These type of capacitors are usually polarised, so just watch that if you do this.

 

Interesting! I will give this a try. :) thanks for your help! Will update to see if it makes the trick. :)

[Mini Manannán]

Many of these modern Radios have 2 supplies to them, one that live all the time, to keep the radio stations in memory and keep the clock running, while the other supply is from the key to bring the music box alive.

Most I've found actually run from the Live feed and the key circuit essentially activates a relay or an electronic equivalent inside them, which senses voltage level rather than voltage presents to do the switching.

When you honk the Horn, hit the spots etc it causes a momentary dip in the voltage that causes these 'smart' circuits to think the car's being shut off, but the voltage quickly rises again to a level where it will be on, but as they are 'smart' circuits, they have a small mini computer that takes time to shut down and time to boot up again,,,,

Most of the time, I've just added a 3 amp diode to the circuit that comes from the key and then added a big capacitor, around 2000 or 4000 microfarad to the radio side of the diode. This usually stores enough power to keep the music box alive over these dips in power and the diode stops them trying to keep the whole car alive from the capacitors. These type of capacitors are usually polarised, so just watch that if you do this.

Goddamn Chris, you are the font of all knowledge!

Edited by Mini Manannán, 18 June 2020 - 09:52 PM.

[GermanMoreno]

Hello, Issue solved,
Stereo shop had done a bad job at hooking up the stereo and amplifier power. They tapped into ignition for amplifier and head unit (Yikes). bad practice, It has been fixed. Radio runs now from fusebox, new ignition installed as well !
No more voltage drop. Everything is dandy.